2B(a)DEMON SLAYER
by TheStrangerThatCameFromNowhere
Summary: Humans believed in the idea of reincarnation, and when humanity once thrived, there was a genre called "isekai." 2B had no real reason to learn about things unrelated to her objectives. She was a machine. She didn't have a soul. Someone upstairs thought otherwise. Her mission had not changed, even as a reborn human in a world inhabited by demons. Glory to mankind
1. 01

**DISCLAIMER**: I do not own Kimetsu no Yaiba or NieR. Both are properties of Koyoharu Gotōge and Yoko Taro respectively.

I do not own the cover art. All credits go to Deviant Artist dishwasher 1910.

* * *

**2B(a)DEMON SLAYER**

* * *

CHAPTER_01: The Machine Girl Reborn As A Human

* * *

Her body was breaking. Every single part of her was tearing itself apart. Her conscious thought was on the verge of crumbling. Her memories were slowly fading, but she wouldn't let that happen. She refused to allow those precious memories, her identity, slip away. So long as she had those, she could continue moving. She could maintain a firm grasp of her sense of self.

But, 2B knew that couldn't last. By now, all of her functions had gone to hell. She could barely hold up her sword properly as two machines stared her down, glowing red eyes glaring at her with malicious intent. One approached in a slow walk, almost as if it was imitating a predator intimidating its prey. Weakly, she raised her sword in defense. The machine struck, knocking her away easily and falling right near the edge of the chasm below.

She gritted her teeth and tried to stand back up, only for an overwhelming pain to consume her mind. Her body locked up, feeling something dreadful and cold slither into her systems.

_'Get out.'_ she screamed back at whatever was trying to take hold of her. _'Get out of my head!'_

The machines raised their swords, ready to deliver the final blow. To 2B's surprise, however, they were swiftly cut down before they even had a chance. A familiar figure, garbed in tattered clothes and long white hair, stood there with her sword drawn and the machines cut into sparking pieces.

"A2..." 2B muttered her savior's name in surprise before hissing in pain. Her fingers twitched sporadically, and her eyes felt like they were burning. She gripped her sword, using it as a makeshift stand, but fell to her knees.

Something was worming its way into her head. Something her systems couldn't understand. A terrifying malice that was corrupting her, trying to take away everything she was. To erase her and replace this husk with something else. A mindless, insane drone that could only slaughter and kill and cut apart anything around it. The only reason it hadn't been able to do so was through her own force of will, struggling with every fiber of her being to keep her memories from being torn apart. But she couldn't last for much longer.

This was her limit.

"Guess this...is it..." 2B smiled sardonically as she cut away her blindfold and opened her eyes. A2 gasped and saw what should have been clear blue eyes were now glowing red. The sign of infection. "These are...my memories...!"

She refused. She refused to relinquish them. She refused to let this...thing delete them. She refused to lose herself. She looked up at A2, who stared back in sorrow. She wondered how many times she must have watched this scene play out. To see people she once considered allies or comrades to become corrupted. Or maybe A2 simply felt sorry for her.

"Take care of everyone for me..." she asked. No, pleaded. She begged A2 to do this one last thing for her. She hoped the android would do this. It was, after all, her last request. "Take care...of the future..."

A2's stare lingered for a moment, then decided. She approached 2B and took hold of her sword, pulling it from the ground. 2B smiled softly as she closed her eyes, then waited. A second later, she felt cold steel pierce her abdomen. The last vestiges of her strength began to fade. All of her systems went critical as warnings sounded off her head. She was dying, or what passed for dying in a machine. That thing was pulling away, realizing it couldn't make a pawn out of her.

"2B! Are you...!"

Blue eyes opened for a final time as she turned her head. She couldn't quite see who was standing on the bridge, but she could never forget that voice. The voice of the person whose life she had ended countless times.

"Oh... Nines..."

Her eyes closed, and her body shut down. Everything turned to black.

The android known as 2B was dead.

* * *

**_NO, NOT YET. YOU CANNOT BE ALLOWED TO PERISH JUST YET, DAUGHTER OF YORHA._**

**_THERE IS STILL MUCH FOR YOU TO DO. _**

* * *

"Ooh, she's awake."

2B stirred from unconsciousness. Slowly, her eyes opened up and saw a man staring down at her. His features were unfamiliar and odd, shell seemingly made of tender flesh. Everything was blurry and a mix of colors. At first, she thought there must have been something wrong with her visual ocular system, then stopped to think. Why in the world was she awake? Did Nines create some kind of backup unit for her? No, that didn't seem right. That should have been impossible, given that her body was corrupted. YorHa had already established that even a non-functioning machine was still infected as a corpse.

"Kiyo, look. She has your eyes."

A woman entered her field of vision. Like the man, her shell was seemingly made of flesh, albeit pale. There were dark rings underneath her eyes, partially glazed over and blank. The visual symptom of being blind, but that couldn't be right. Androids couldn't become blind. Even if they did, their eyes wouldn't develop that symptom. Only humans did.

"Does she?"

"Yes. Very clear blue." the man smiled. "And so small."

Small? What was he talking about? She was designed to be the size of the average female human. She opened her mouth to question who he was and where she was located-

"Aaa?"

-and spoke in babbling gibberish.

2B's mind shut down.

_'...huh?'_

"Aw, look~ Little Yona's trying to talk!"

_'What?!'_

She opened her mouth again. But instead of coherent words questioning about what was going on, all that can out was:

"Aaa?"

What was happening?! Was there something wrong with her vocals?! No, wait. Calm down. If she couldn't communicate verbally, then maybe she could communicate with actions. While sign language was not entirely in use among androids, it was still viable in the event their voice was unusable.

...wait.

_'Wh-why are my arms so small and tiny?!'_

Instead of the lithe, hard limbs that she was used to, all she saw were two small, pudgy arms and hands. They seemed to be incredibly soft. Despite this startling revelation, she resolved herself to try something. She tried to sign out symbols using her fingers...only to end up moving them awkwardly and uncontrollably.

_'What happened to my motor reflexes?'_

There was something else wrong as well. Her inner systems felt off. Very off. Actually, all of her body felt off, and not just her mouth and limbs. It was like all of her functions were haywire or wouldn't work right.

_'Something here isn't right. Why can't my body work properly. Is this...an after-effect of the logic virus? None of this makes sense. Who are these two? And why am I in such a small, defective body?!'_

If this was some kind of practical joke, it was far from funny. She needed to get back to 9S and the others.

Suddenly, the woman started to cough haphazardly. "Kiyo, are you alright?" the man asked worriedly, still holding the tiny 2B. "If you aren't feeling well enough yet, I can..."

"No. I..." The coughing fit subsided. "I'm fine, Yukito. It's not as bad as it was the other day. Can...can I hold little Yona?"

"Of course."

_'Will you people stop treating me like I'm some kind of child?_' thought the irritated 2B. _'Why do they keep calling me Yona? Who are even these machines?'_

With gentle hands, the woman called Kiyo held 2B in her arms and peered down at her face, a finger brushing up against her cheek. The sensation was different compared to the other times 2B had physical contact with another person, but she didn't understand why and chalked it up to another defective function of her body.

"My beautiful Yona..." the woman cooed. "My darling daughter... Oh, how I hope you live a beautiful and wonderful life..."

2B stared at the woman for a moment. Her brain lagged for a minute before Kiyo's words caught up to her.

"Aaa?!"

_'WHAT?!'_

That night, the infant 2B could only scream out in confusion and shock at the woman's words until her body was consumed by exhaustion and forced back into slumber.

* * *

In the past, there was a belief that humans once had. An idea that, when a human dies, their soul would enter the cycle of karma and be born into a new life and become a new person, walking down a new path. In the past, there was a genre in human literature called "isekai," in which a person would be brought to a new world either by death or being brought there at the hands of a powerful force or ritual. 2B knew about these concepts, as well as various other bits of information, but they were all so trivial and meaningless to her duties as part of YorHa that she couldn't have cared less about those plans. Instead, she focused on her given tasks and took down any threat to YorHa deemed dangerous enough to warrant action.

Had she known that this would have happened to her, she would have looked it up.

Ten years. That was how long she had spent in this body and world. In the body of a human being - the extinct race that she had been sworn to serve and protect. In this bygone age in the land of the rising sun known as Japan.

At first, she had been in complete disbelief and shock. She refused to believe that it was possible, as the idea of reincarnation was a mere myth and "isekai" born from the minds of otaku, or at least she assumed that word was correct. She thought that someone must have put her Black Box and stuck her inside a tiny defective body in androids who were disillusioned. Her infant years were quite the adjustment period as she was constantly trying to get away from the people who called themselves her parents. She even refused to be fed breast milk, much less believe that an android was designed with that function. Granted, androids were designed to look like humans, but who in their right mind would try and design them to perfectly replicate them?

It was only when she was a year old that she finally started to understand her situation, where she developed what was known as a fever.

It was a new experience. A dreadful one. One she couldn't even compare back when she was infected. Her body felt overheated. Her mind was clouded. It even became difficult to breath, a new sensation for her. The ones who claim to be her parents were wrought with worry as they tried to nurse her back to health.

It was the first real sign that this was a human body. That she had been reincarnated.

But that brought forth a very confusing conflict in her mind. Namely, why she was reincarnated. She was an android. A machine, built from metal pieces and wires and fluids. Made to replicate a human body and could express a semblance of human emotion. If a soul did indeed exist, then why would a machine have one? Why was it possible for someone like her to be reborn in the past as a human being? She who was made entirely of metal?

She couldn't understand how this was possible, but it was. She was unable to understand the logic of how it was possible, but the evidence didn't lie.

Growing up, 2B had done her best to try and mimic the lifestyles and customs of humans in Japan while understanding exactly where and when she was. Preliminary investigations told her she was living in the Yokohama region of what would become the central Tokyo region. Based on living conditions and the typical styles of the homes within the area, 2B believed that she was currently in the Taishō Period, which began in 1912 and would eventually end in 1926.

At present, winter had arrived to Japan and made its presence well-known by blanketing the village in snow. The roofs were caked in white sheets of crystallized water. It wasn't the first time 2B had experienced the cold, but somehow it felt worse than in the decade she had spent growing up. The yukata did little to nothing to keep her warm. And a human body, unlike her old android one, couldn't regulate her body temperature fast enough or provide her with warmth as well. She was forced to rely on the body heat radiated by the man who raised her.

"Are you cold, Yona?"

2B shook her head. "I am fine, Otou-sama." she said respectfully.

Growing up, she had come to accept her role as a daughter. She had come to accept the two humans as her parents. It was an unusual experience.

Yet...it was not an unwelcome one. For the first time in her life, she felt a warmth like never before.

She had no experience with people acting the role of parents. In fact, the closest thing she had to a relationship was with 9S and Operato 6O. Having parents was an unusual but beautiful learning experience, though she would have preferred her father not smothering her when she was in the single digits. Her reaction to a fever was worrisome for the man, as she learned her mother had also been rather sickly. She suffered from what 2B identified as "tuberculosis," having trouble breathing and suffering from severe coughing fits from time to time. Her condition fluctuated through the yen years 2B spent growing up, but it was only recently that her condition vastly deteriorated.

Today, 2B was experiencing an emotion she felt countless times while partnered with 9S. An emotion she had hoped that she would never have to experience. It was wishful thinking and foolish for her to believe she wouldn't suffer it, considering how her new human emotions had ultimately led to her becoming so attached to her mother. The reason why she was experiencing it was because her father and many others in the village were carrying her mother to a newly-dug grave that was quickly piling with falling snow.

Six days ago, the woman known as Kiyo succumbed to her disease. And today was her funeral.

This had been an experience new to 2B. She was no stranger to loss, as she had been forced to destroy 9S many times back then. But this form of loss was different.

She had spent years forming a bond with her mother. And now that bond has been severed by tuberculosis. The difference between the previous circumstances and now?

Her mother had no chance of coming back. Human lives are finite and limited.

"Yukito, how are you fairing?" one of the neighbors asked, walking beside the father. "It can't have been easy, losing your wife so recently."

2B's father smiled weakly. "I'm fine, or so I'd like to say. Kiyo, she...she was looking forward to the trip."

"Ah, right. You were planning on going to Shanghai, weren't you?"

"Yes." Yukito nodded sadly. "I...I just wish we had more time. Just enough so we all could've gone."

Shanghai, China. One of the four municipalities, and quite a ways off. Ordinarily, Japan wouldn't allow for travel to outside countries, but the Taishō period had a few exceptions, what with western influences beginning to make its way, especially in Kyoto. The reason behind the visit was to see a close friend of 2B's father, who had started up a trading business, or so he told her.

"Well, at least you have little Yona with you." the neighbor offered some consolation. "Poor girl, losing her mother at such a young age too. How are you fairing, little one?"

2B was silent. She couldn't even if she wanted to. These new emotions, these feelings...they were simply too overwhelming. She pressed her face into the yukata of her father.

They were approaching the place where she would be buried. The last time 2B would ever lay eyes of her mother, dressed in a pure white kimono, skin freshly cleaned and hair undone, eyes closed.

She looked to have been peacefully asleep. Alas, it would be a sleep she would never wake from.

The villagers gathered around the grave and watched with misty eyes, some openly weeping, as 2B's mother was gently set into the grave. A small candle was lit at the wooden headstone as the priest began to recite the parting prayers. The funeral was an experience 2B never felt, and though she couldn't quell this unusual feeling swelling within her, she watched as they shoveled dirt into the grave, soiling her mother's beautiful face and pure white kimono. The bits of grime and earth mixed together with the falling snow.

_'So, this is what a human funeral is like.'_ She compared it to the funerals of an android. Nothing teary as this, but still somber. 2B witnessed many comrade's inoperable remains set into a furnace, so as to prevent its remains from being used by scavengers or being desecrated. _'It's...much more depressing than I thought it would be.'_ 2B looked up at her father. The man's face was screwed up, eyes shut while rivers flowed from his cheeks. Droplets from those rivers spilled to her face. _'He's crying... A normal human child should be crying also for seeing this. I should be crying, but...can I cry?'_

Her silent question was answered as her vision blurred. She blinked, and her sight was still misty. She gingerly reached up and brushed her eyes, only for her fingers to become damp. She stared at it for a moment, then felt something wet cascade down her cheeks. It took her a second to realize that these were tears. Genuine, true tears.

The tears of a human being.

_'Humans are...an odd species...'_ 2B thought as the feeling that had been with her for the last couple days tightened its grip on her. As her mother's face became covered with dirt, she turned away and pressed her face into her father's chest. He took this as a sign to hold on to her tightly and gently pushed her further against him. 'These emotions...these are what humans feel every day.'

She wished she had been brought to this time as a machine. At least then, her settings could prevent her from fully feeling these complex emotions. Perhaps this was the reason why machines were explicitly to never feel anything. She was drowning in emotions and feelings that she still couldn't understand properly. Had this been 9S, maybe he could have found a way to deal with this. Despite his own words that machines and androids, even those who pretended to emulate human emotions, couldn't truly express what it meant to feel and act like a human being, he understood. It was why she had killed him so many times. Because it was those same emotions that kept pushing him forward to discover what YorHa had been hiding from him.

_'Nines...'_

She had thought about him and A2 for a very long time. How whether or not they too were reincarnated in this place or if they were okay. She couldn't see the expression 9S had back then, but she could hear the fear and horror in his voice. He must have been chasing after her around the time the Logic Virus had started to take root inside her body. How often had she chastised him for expressing such emotions? How many times had she killed him and felt what he must have felt?

Her tiny hands trembled as she recalled the feeling.

"It's alright, Yona..." her father whispered to her through his sobs. "Everything...everything will be okay..."

No, it wouldn't. Not as long as she remained 2B, the android girl who had been reincarnated into a world that had no place for her.

* * *

The funeral had ended hours ago. After a moment to herself and without her grieving father hovering over her, 2B had managed to regain a form of control over her human emotions. She hadn't realized it until now, but the experiences she had as an android were conflicting with who she was at this moment. The android 2B was a battle-hardened soldier and warrior of YorHa, while Yona was just a mere 11-year-old girl who had the memories of 2B. A human who experienced emotions in full, not the subdued replica emotions androids knew. They were forbidden for feeling genuine emotions.

_'But, I can't do that anymore.'_ 2B thought as she stared at her hands. They were so smooth and soft, not unlike the rough and metal hands that held countless weapons that cut down innumerable machines and former comrades._ 'I can't regulate or suppress emotions anymore. I'm experiencing so many things now...'_ She furrowed her brow. _'Things are different now. I can't think the same way anymore. So many emotions are conflicting within me, and I don't know how I can stop them.'_

It was truly a conundrum. The emotions within her swirled, churned, and raged like a hurricane. And no matter how hard she tried, she just couldn't bring them under control. She was losing to them.

She thought she had gotten better at handling them, but after today, she wasn't so sure.

_'I underestimated the complexity and force of human emotions.'_ 2B declared. _'It's little wonder why androids were forbidden from feeling them.'_

Logic and reason were how they operated. Emotions, especially one as powerful as human emotions, could influence a person's actions greatly, be it for good or ill. But if one acted within reason and thought logically about the intended course of action, then they would obtain the best possible results. That was how 2B had always acted. She was sure if she had such emotions, she would have been a total mess and constantly fumble, perhaps even sympathize with the machines that she and YorHa considered to be enemies.

She sighed to herself and shook her head. If she continued to think about such things, she would surely drive herself mad trying to find a way to subdue these overwhelming emotions of hers. She stood up from her bed and left the room, bare feet tapping against the mats underneath her.

The comfort she experienced within this decade had been a wonder indeed. The term "culture shock" came to mind and best described what growing up in the Taishō period. While she had knowledge of Japan's otherwise "golden years," she never truly understood what the documents and historical texts had to offer until she began to experience them for herself, and learn the limitations of the human body. Though she was a human child, at her core she was still 2B, one of the best warriors at YorHa's disposal. Fighting was in her blood. But her body was so weak and frail, if she even so much as tried to replicate what she could do back then, at best she'd fail and have a couple broken bones. At worst, well, she would have demolished her body completely and died trying. A human body, even at the peak of physical strength, could never replicate the ability of a machine designed for war.

Thus, as the human child Yona, 2B experienced a life of complacency and safety. She needn't ever worry about fighting or drawing a sword unless she pursued the path of a warrior. Down in her bones, she could feel that yearning desire to hold a sword. But she refrained and lived the life she was expected to lead in this period. A woman in Japan was expected to be courteous, self-reliant, compliant and modest. As a child, she was expected to listen to her father. When she was to be wed and married, she was to listen to her husband. And when she had become old, she was to listen to her son. This was what was expected of 2B in the coming years as she entered adulthood and lived the life of a human. The odds that she would ever come to hold a sword would be quite low.

And yet, that was what 2B wished. To remember and feel the weight of a blade in her hand.

Perhaps as a result of such thoughts, 2B found herself in the living room. The candles had long since been blown out and the winter clouds blocking out the moon, so the room was eerily dark. The air was cold and left goosebumps trailing along her skin, causing her to shudder. She approached a small shrine up against the wall containing a candle whose light had recently been extinguished and a photograph. It was not her mother's, but instead of the man who had been the father of her male parent. A grandfather. Evidence to this was his wrinkled face and frost-white hair. However, her attention was not on the photograph, but instead on the item held up on a wooden rack up above it.

A katana. Its hilt cold gray and the handle wrapped in thick, woven white thread with black diamond shapes running down the middle. 2B knew not the state of the sword within its sheathe, but the scabbard itself was beautifully crafted and made with a true passion, a sleek black refurbished wood with white and black designs, reminiscent of a portrayal of a breeze.

2B stared at the sword longingly, reaching out to touch it. She stopped and pulled her hand back, shaking her head. What was she doing? The sword was not hers. It belonged to her deceased grandfather. She didn't have the right to wield it.

No matter how much she wanted to wield the blade again, she did not want to disrespect her ancestor and family.

"Yona?" Startled and surprised, another testament to the contrast between a human body and a machine and showcasing how the mighty had fallen, 2B turned around and saw her father Yukito entering the room. His eyes were puffy and red, showing that he had been sobbing all night. "What are you doing out of bed?"

"Forgive me, Otou-sama. I could not sleep." 2B replied honestly.

Yukito's face softened. He saw her standing in front of the shrine. "Were you offering prayers to your grandfather?"

"Yes." At least, that was he believed so she wouldn't correct him. She let her curiosity get the better of her and looked back at the sheathed katana above the shrine. "Otou-sama, that sword... This belonged to Ojii-sama, right?"

"Ah, that..." Her father walked over to her side, carefully removing the katana from its rack and kneeling down. "You want to see it?" 2B nodded. He withdrew the sword from its sheathe and 2B gasped.

Before, she cared little about the design of any weapon she could get her hands on. So long as they performed well enough and helped her succeed in her missions, there was no reason for her to take a moment and admire their craftsmanship. But this time was different. This time, she couldn't help but stare in admiration at the katana's naked blade.

"Beautiful..."

A beautiful silver-coated sword, almost the color of moonlight. The edge was sharp and not a hint of rust, showing that the sword had been carefully maintained throughout the many long years it had been crafted. She had never seen a blade with such a color, nor one as finely crafted as this. As she took in every detail, she noticed something was carved into the blade near the hilt.

"Destroy...Demons..." she whispered aloud before looking up at her father. "Otou-sama, what does that mean?"

"Ah. I almost forgot about that." He said in nostalgia. "It's...a motto of sorts. A creed, if you will."

"Motto?" 2B tilted her head in confusion. "Creed?"

"Yes. You see Yona, your grandfather was a skilled swordsman. In fact, from what I recall, he was one of the very best back then."

"He belonged to an organization whose duty was to defend the people. You've heard how everyone talks about the demons, right?"

2B nodded. She had heard such talk, but she didn't put very much stock into it. Demons were just fairy tales and myths used to symbolize calamity and illness. There was hardly any actual proof behind their existence. That was one of the things that befuddled the former android, how humanity's imagination could find ways to explain explainable phenomenon at the time. All these talks of disappearances and brutal murders were the work of vicious animals and humans consumed by depravity. She didn't say as much to her father and let him continue.

"Your grandfather... Sakazuki-san, was a demon slayer." Yukito said to her surprise. "The Demon Slayer Corps purpose was to eliminate the demons. There are two ways you can identify their number. The first is their dark clothing. Almost all of them are dressed in black clothes and are usually accompanied by a raven or a crow. The second way is what you see here." He pointed to the engraving on the sword. "All demon slayers carry a sword with this engraved into it."

"I see..." 2B nodded. Though she was still skeptical about the existence of demons, perhaps they were actually vigilantes or something of the like. "Then, they're like the police?"

Her father shook her head. "No, they are not. You see, the Demon Slayer Corps is an unsanctioned organization and isn't part of the government. While many people know about their existence, and the police do aid them on occasion, they're otherwise working outside the law and liable to get arrested depending on the situation."

"But...that doesn't seem fair." She stated. The Demon Slayers protected people, but they're still liable to get arrested? That seemed counterintuitive.

"That's what I thought when my father first told me about them." He chuckled. "But there is a reason why they're separate from the government. It's to minimize the exposure of civilians to demons. If the entire populace knew about them, they'd fall into panic."

"To everyone else, the demons are just whispers and rumors. Signs of calamity, some say. But in truth, they exist." Yukito smiled wryly. "Of course, I've never seen one myself. I imagine I'd have soiled myself silly if I had!" He slid the sword back into its sheathe and returned it to the rack. "Now, enough talk of monsters. I can't have you getting nightmares. Off to bed now, Yona."

2B nodded. The two parted and returned to their rooms, but the girl was now slightly intrigued about this Demon Slayer Corps organization. Was it possible that they were like YorHa? Were the demons something else? The more she gave the matter some thought, the more curious she became.

"Aaaah~"

A yawn escaped her and made her realize her body was exhausted, physically and emotionally. It would be wise to get some sleep and think about this for another day. She slipped back into her room and settled beneath the blanket, closing her eyes and letting unconsciousness seep into her mind.

* * *

The next morning, Yona awoke to find that their home had a new occupant. A guest had arrived sometime in the morning, having traveled a great distance and was in search of lodgings. Her father, being the bleeding heart that he was, gave the stranger shelter in their home but not without setting some groundrules first.

2B felt her instincts flare the moment she saw the guest. A towering behemoth with short hair and blank eyes, obviously blind and bearing a scar across his temples. He was clad in a tattered robe, but there was no mistaking the hilt of an ax sticking out from beneath the cloth of his cloak. Around his neck were large crimson prayer beads, with similar but smaller beads around his hands.

"I do apologize for intruding on your home so suddenly, Yukito-sama." the towering man said humbly. "I have traveled a great distance and had hoped to find a suitable hut, but..."

Her father waved a hand in dismissal. "It is fine. It's a shame you came at such a bad time, though. The winter this year looks to be a brutal one."

"I have noticed. Many of the roads have either become piled with snow or frozen over. Even the lakes have turned to ice."

"Indeed. Pardon, but I never caught your name."

"Himejima, sir. Gyomei Himejima."

"Well, it is nice to meet you, Himejima-san." Yukito bowed. "You're welcome to stay until the roads become clear. I wouldn't want anyone to be caught up in the cold this time of year."

"I am truly grateful for your hospitality." He clasped his hands together in prayer.

2B continued to stare at the man in curiosity. Though he seemed gentle, 2B had long since learned to identify a potential threat. He looked kind and gentle, but those hands were rough. He was a warrior and had fought many battles.

_'Is he a threat?'_

She glanced at the sheathed katana above the shrine. Even in this small body, could she take him down if he were to turn his blade against her?

2B already knew the answer before the thought even finished. She couldn't. This was not her old body. She was weak and untrained. Even if she could replicate the feats she had done in her android body, she'd break her body in doing so. In fact, she believed that the man would be capable of ending her life before she had a chance to withdraw her sword from its sheathe.

Fighting this man was suicide.

"What are you doing there, Yona?" her father saw her hiding away around the corner and smiled weakly. His eyes were still red and puffy. "Come and greet our guest."

"...yes, Otou-sama."

Almost reluctantly. She made herself known to the potential threat. She just hoped that he was not a threat. If he was, then she couldn't do anything about it. Not with her current body the way as it is. She gingerly approached, footsteps alerting the man of her presence. He craned his head in her direction. "These footsteps...a child?"

"My daughter, Yona." Yukito introduced her to him. "She can be quiet at times, but she's quit the studious girl. I don't there have been as many girls her age who can read so much in a month!"

"Is that so? Forgive me for being blunt, but what of her mother?"

The mood immediately turned somber. Yukito's smile dimmed. The memories of yesterday's funeral caused those unpleasant emotions to swell up inside her chest. "Okaa-sama is dead." 2B informed him, voice tight. "Her funeral was yesterday."

"Ah, I see." Gyomei said solemnly. "I deeply apologize. You have my condolences." He clasped his hands into a prayer for the departed.

To both people's surprise, his eyes turned watery and tears spilled down his face like a river. 'Do humans cry this easily...?' 2B wondered to herself in curiosity. 'So strange.'

"Yona, can I ask a favor of you?" Yukito shook off his shock and addressed his daughter. "Can you run by the market and see if Mitsuri-san has any firewood? Just tell him your daddy sent you, okay?"

2B nodded. "Of course, Otou-sama." After he handed her a small amount of currency for the wood, 2B bowed and exited the room, leaving the two men alone.

Truthfully, she wasn't entirely comfortable leaving her father with a potential threat. He was a stranger she knew nothing about. What if he proved to be dangerous and planned on killing them? Or used them for some nefarious purpose?

_'Good grief. I sound so paranoid.'_ the former android sighed deeply. She slipped on her sandals and tightened the grip of her kimono before she left the house and set her feet into the snow. The air had warmed slightly, but the frigid chill was still poignant enough for her to feel the cold snow through the sandals. She shivered slightly and quickly made her way to the market. _'You would think that living in this body for a decade would help me become used to its flaws. What wouldn't I give to have my old mechanical body back...'_

She never noticed the black crow watching her carefully, perching atop the huge oak tree sitting beside her home.

* * *

2B arrived at the market without a hitch and saw that most of the villagers had recovered from yesterday. Some were still affected, those who knew her mother very well and could be considered friends with her, whereas the others simply attended out of respect. While they knew Kiyo to some level, they otherwise knew her as a neighbor and frequent visitor in the market and bought their wares on more than a few occasions.

As she walked with her bag of coins safely secured in her kimono, a group of children rushed by her and would have kept going, had one of them not recognized her.

"Hey, is that Yona? Yona!"

2B turned and saw the children approach. She often played with them with mixed results as she tried to pass herself off as the child she was in this body. It was actually harder than she thought, as on several occasions these kids tested her patients in a way she never thought possible. Not even 9S at her most annoying was as bad as them! It was only a true monument to her patience that she prevented herself from lashing out from their absurdities. They were children, after all.

"Masaomi-san." 2B bowed her head. "Good afternoon."

"What are you doing here by yourself?" the leader of the children, Masaomi, asked. He was the eldest of the children and the son of the village elder, perhaps a year or two older than 2B herself in her child body. "Shouldn't Yukito-jii-chan be here with you?"

"No, he is entertaining a guest who arrived in the morning. He traveled a great distance and is unable to travel further because of the snow." she answered honestly. "He asked me to retrieve firewood from Mitsuri-san. What about you all? What are you playing today?"

"We're not playing anything." Masaomi said, a wide grin forming on his face. "We're demon hunting!"

2B frowned. "Demon hunting? Masaomi-san, do you believe demons exist as well?"

"Of course!" the boy replied. "You remember Takeomi-san, right? The butcher's daughter who went missing?" 2B nodded. She remembered that particular nightmare, as it occurred a few days before her mother's illness consumed her. She suddenly vanished in the middle of the night and was nowhere to be seen for several days. The whole village went into an uproar and scrambled to try and find her. "Well, this morning, one of the villagers found her!"

"They have?" 2B inquired. "Why has no one spoken of it yet?"

Masaomi's eager look faded a bit. "Ojii-chan isn't really sure how to break the news to everyone. I haven't actually seen Takeomi-san, but I heard one of the adults say that her face was torn off."

"What?!" 2B gasped in shock. Her face had been torn off? How cruel!

"That's what the adults say. But we haven't seen for ourselves, they wouldn't let us."

"That's why were going after that demon!"

She stared at the children in a mixture of shock and anger. What did they think they were doing?! Were they trying to get themselves killed? They were children and couldn't fight, much less hold a sword properly! If what they said was true, then they were going up against a truly depraved man. That meant they were dangerous. Something like that shouldn't be entrusted to kids. Even 2B knew that much.

"Why don't you come with us, Yona?" one of the girls in the group asked. "Your dad has a sword, right? You should bring it with you!"

2B scowled. "You're fools." The children stared at her in shock. "Do you not hear what you are saying? You are trying to find someone who has no qualms about killing, especially in such a brutal fashion. Say you find this 'demon,' what will you do? Try to fight it yourselves? Have you had any sort of training with weapons?"

"W-well, no..." Masaomi quickly wilted. "B-but, what if-"

"Masaomi-san, I understand you mean well, but think of the consequences. What if one of you dies and must inform your parents of what has transpired? What if you all die and we must find your corpses?" Her glare hardened. "This village has just another person, including my Okaa-san a mere week ago. Would you truly subject us to the loss of more?!"

"The girl speaks the truth, little ones." To 2B's surprise, the giant that was Gyomei appeared. The children gawked at the man, having never met someone of his stature before. "To fight a demon is foolhardy, much less suicidal without any form of training. Think of what would happen should you fail in your endeavor. As Yona-san has said, the village is already in grief. Please, do not make it worse."

"T-that's..."

The fire in Masaomi's eyes died and lowered his head. One of the other children put a hand on his shoulder and shook his head. Discouraged and losing their drive, the children moved on.

Gyomei looked in their direction for a moment, as if to see them off, before he turned his attention back to 2B. "You are very wise, Yona-san."

"Thank you for your kind words, Himejima-san." 2B replied courteously as she bowed. "What brings you to the market?"

"I merely came to see if there was a butcher shop. Yukito-san mentioned having meat, and I offered to cook."

2B stared at him suspiciously. "Please pardon my rudeness, Himejima-san, but are you blind?" The man took no offense to her words and nodded. "How can you cook if you cannot see?"

"I have had years of practice, little one." Gyomei replied. "I once took care of a small band of children such as yourself when I was a monk."

"You're a monk?" She questioned. Granted, she probably should've had such suspicions given his accessories and behavior.

"I am. I'm currently on...let's say a pilgrimage. I'm traveling the country as per my instructions."

"Instructions for what?"

"To give guidance." Gyomei answered. "Yona-san, speaking honestly, what do you believe of this talk of demons?"

2B pursed her lips, wondering how she should answer. "...I do not believe that monsters exist." she answered after a moment of decision. "They are what people use to explain calamity and misfortune. However, if there is someone behind Takeomi-san's death, it is a depraved human being who acts like an animal than a human being. No human being would tear apart another's face for whatever reason."

The monk remained silent as he processed her words. Finally, he spoke. "I see. As I said before, you are very wise for your age, Yona-san. I understand your point of view."

She could tell there was more he wished to say, but he chose to instead speak silence and moved on. 2B watched him with an eagle's eye, now more than ever wary of this stranger. She did not know why he questioned her about the existence of the demons, but she did find his timing to be quite odd. A stranger arriving in the village, around the same time Takeomi's body had been discovered? Was it possible that he was the culprit? His stature and overall build suggested it would be possible for him to do it, but 2B had no evidence. Only her suspicions. and his overall presence.

She needed to keep an eye on him. But first, she needed to buy wood. And tell the village elder what his stupid son was trying to do. Though Gyomei and she had managed to deter him from this course of action, she knew him well enough that Masaomi would still try to hunt the demon. He would surely find himself in an early grave.

She did not wish to experience more negative emotions than what she was already experiencing. She had witnessed her mother, a grown woman that had raised her for eleven years, be buried. She did not want to experience what sort of turmoil witnessing a human child being buried would bring.

_'Children...'_ 2B's memories went to a group of machines she and 9S had encountered so long ago. How Pascal, the leader of a community, was just trying to provide a safe haven for those wanting to live in peace. Away from the chaos instigated by those infected by the Logic Virus. She recalled what had become of the community and of the mechanical children Pascal had tried to protect.

Her hands trembled and shut her eyes. Her emotions surfaced and felt streams forming down her face.

She would not see another child, much less a human one, die.

* * *

Night had arrived. The sky was clear and the moon was full. He could tell by the way the light it radiated fell upon the small village, a bloodthirsty monster in its midst.

Gyomei Himejima had not been lying when he had said that his travel had been cut short. The unexpected winter's severity had blocked off most of the routes leading into the village and had gotten lucky when he arrived. To his disappointment and sadness, he arrived a couple days late.

A demon had already claimed its victim.

He lamented his lack of speed and caution. If he had left earlier, he probably could've made it to this village in time to save the victim. Alas, he was too late, delayed by a force of nature. But he lamented and moved on. What was done was done.

The demon had been running rampant two days too long. It was time to put an end to its sorrowful existence. He intended to patrol the village tonight and see what he could learn, as he couldn't simply just hunt for it without anything to go on. All he knew was its preferred method of killing. Some demons were known to devour humans in unique ways. For this case, Gyomei believed that the demon loved to devour humans by eating their face. As to why, well, he was not interested in learning why. Only saddened and dismayed that even a demon would marry another person's body in such a manner. A truly lamentable soul who deserved to be laid to rest post-haste.

It wouldn't be very hard to find the demon in a village as small as this, but the Hashira was concerned. The daughter of the man who offered him lodgings, Yukito, was a sharp one.

The young girl, Yona, was unusually wise and perceptive for a girl her age. He may not be able to see the maturity in her eyes, but her tone of voice, the way she spoke, and the way she carried herself told the man many things. But the more he thought of her, the more saddened he became.

Just what experiences had the girl gone through to behave in such a manner? Children deserved the right to live out their childhood days in peace, as it is a privilege many have lost due to existence of demons. While his opinion of children may have lessened over the years, considering the circumstances that led him to becoming a Demon Slayer, Gyomei still cared greatly about them and prayed that she would regain a happy life.

Perhaps that day would come when the demon was dead. After checking his gear, he nodded to himself and stood up. Carefully to not make any noise, he fled the household and entered the snowy world outside the home, katana at his hip.

It was time for the hunt to begin.

* * *

2B woke up to the sound of someone leaving. In truth, she had only been half-asleep as she had been plagued by nightmares earlier in the night. She was restless and could barely find the strength to return to slumber when she heard the soft and near silent footsteps of Gyomei Himejima. She left her room and peered down the halls, finding the man making his way for the entrance. To her surprise, his robe was gone and revealed a green coat over a black uniform, his sword now in plain view.

The words her father spoke to her the night before came to mind. Warriors garbed in clothing as dark as a raven.

"Demon Slayer Corps..."

Seriously, what the heck was this? She heard of coincidences, but this was just divine intervention at work or something. Assuming god did exist.

If one was here, then did that mean the murder was the work of a monster? Or a depraved human murderer? She did not know for certain. Everything just seemed to line up with what her father told her too well. Her curiosity grew more and more. Before she realized it, her feet led her to follow the blind man out in the snow. She made sure to keep her presence quiet and her footsteps as light as she could, stepping in the same footprints the man did to lessen the sound of the crunching snow. She felt the chills of the winter night. She pulled her kimono closer in an attempt to stay warm as she continued her pursuit.

The way he moved reminded her of A2. Driven and absorbed in a mission that he would see through to the end. A dedication few at YorHa, including herself, had. His hand also never left the hilt of his ax, either, as if he fully expected battle at the drop of a hat. His movements were slow and calm, and he kept his surroundings in full view. Though he had lost the ability to see, he relied on his other senses. Smell, hearing, taste and touch. Senses that became enhanced with the loss of one of the more vital senses in order to make up for the loss. With that in mind, perhaps he knew 2B was following him and paid it little attention. Or perhaps he didn't notice, but that was doubtful. This was no amateur, but a master of his craft.

With those thoughts in mind, 2B wondered what it was he was hunting that warranted such reaction. Whoever or whatever the "demon" was, it was dangerous enough to elicit a man ready to kill without a second thought.

They entered the market street, which was now devoid of life. The lights were out and not a soul in sight. It was utterly lifeless, and the harsh cold was not making things any better. 2B ceased movement and hid behind one of the shacks when she saw him stop. 'Have I been found out?' What would he do if he discovered her? Silence her to prevent her from speaking of this? Tell her to keep quiet? She saw him look about, eyes closed and his ears twitching, straining to her the faintest sound. Seeing this, she put a hand to her mouth, held her breath and slowed her heart as much as she could.

He was trying to discern any peculiarities through sound alone. If she so much as exhaled or twitched, he would find out about her presence. She had to keep quiet until he moved on.

...if only her human body didn't have to require breathing. She underestimated how long she could actually hold her breath with her current body. She started to feel her lungs burn and cry for air.

To her relief, Gyomei moved and walked further. Once she was sure it was safe to breathe, she exhaled and gulped for air. Once she swallowed enough oxygen, she prepared to continue her pursuit, only to stop when she felt a presence behind her. Out of the corner of her vision, a hand was reaching out for her. Reflex kicked in and her hand whipped out like a viper, grabbing the wrist and pulling her would-be attacker forward. Though her frame was small, she had enough strength to cause the average adult stumble. She then followed up with a swift knee kick, aiming for a man's most vital area.

"Guh!"

Only to instead strike a small waist. 2B stared in shock as Masaomi crumbled to the ground, clutching his stomach and whimpering in pain. "Masaomi-san? What are you doing here?"

"S-same as you..." he wheezed. "I was...hoping to talk...to the big guy." He shakily got up to his feet with a grimace. "He's-he's one of them, right? Those Demon Slayers people are talking about, right?"

"I do not know." 2B replied. Though his attire matched what her father told her, she still did not have confirmation that he was part of the organization. "Never mind that, why are you out this late at night? Couldn't have simply talked to him earlier?"

"I tried, but Ojii-chan freaked out when I told him about this afternoon!" Masaomi whimpered. "He's been really sick the last couple of days. Not as sick as your Kaa-san, but he was pretty bad. The coughing just wouldn't stop. The guy who came by our house, the man in western clothing, he said he could make Ojii-chan better, but ever since then, Ojii-chan hasn't left the house at all. All he does is sit in that dark room of his!"

2B frowned heavily. She had noticed that the village elder had made little appearance in the last few months, but the appearance of a man in western clothing was foreign to her. This was the first she heard of it. If what Masaomi said was true, then maybe he did something that worsened the elder's condition.

"And how does that relate to asking Himejima-san?"

"Because that demon showed up around the same time Ojii-chan's sickness got worse! T-they have to be related, right?"

"That depends, little one." The two children froze. A shadow fell upon them both as the looked up. There stood Gyomei, his blank eyes focused on the two. "Did you speak with your grandfather, face to face?"

_'How did he...?_' 2B stared at Gyomei wide-eyed. _'I didn't hear a sound, and yet he somehow managed to sneak up on us both.'_ She looked around and found not a single footprint in the snow. _'He didn't disturb the snow at all... The buildings here a rickety and would creak if someone tried to run on the rooftop, so how in the world did he manage to...?'_

"W-when did you show up, mister?!" Masaomi squeaked.

The corner of the monk's lips twitched. "I have my ways. By the way, Yona-san. I must commend you for lowering your heartbeat while holding your breath. You have excellent control of your bodily functions."

"Um, thank you...?"

"Back to the matter at hand..." Gyomei turned his attention back to the village elder's son. "Masaomi-san, was it? Did you speak with your grandfather, face-to-face?"

"What? N-no, I didn't. He forbids me and our maid, Tsukume-chan, from entering his room. He said he didn't want us to get sick. B-but..." Masaomi looked down. "W-when I tried to talk to him this afternoon, I peeked inside. I-I could have sworn I saw his sheets stained red. Ojii-chan's never had coughting fits so bad he's start coughing up blood, b-but his sickness got worse when the demon showed up and killed Takeomi-san. S-so..."

"I see..." Gyomei sighed deeply. "How lamentable. Such a truly pitiable existence you have been forced to endure." 2B and Masaomi stared at Gyomei in confusion before he continued. "Masaomi-san. Could you tell me where your home is?"

"Huh? Uh...sure...but why?" Masaomi asked with uncertainty.

"I apologize. But I shall explain when we get there." Gyomei apologized.

Both children were unsure about this, but the man seemed earnest enough. 2B felt a creeping dread crawl up her back. She couldn't tell what it was, but there was a subtle shift in the air. Faintly, as Gyomei was led to the home of the village elder, she could see what looked like a bloody red mist where Masaomi's home was.

* * *

He could hear it. The sound of bloodthirsty desire. The unquenchable thirst for flesh.

Some Demon Slayers had various means of feeling the presence of a demon. The previous Water Pillar before Tomioka was said to possess an incredible keen sense of smell, and the former Roaring Pillar had an impeccable hearing. Uzui also had incredible hearing, though he likened it to having echolocation. Gyomei himself had an incredible sense of hearing. Nowhere near as good as the former Roaring Pillar, but still good enough to hear the sounds of a demon's malevolent intentions. It wasn't guaranteed that all Demon Slayers would possess a unique ability like that, but that was fine. All they needed was their wits about them and a good sword arm and technique.

Judging by the way young Yona stiffened as they grew closer to the demon's den, he could tell she too must have a unique sense. He had suspected her blood ties to his organization when Yukito had accidentally knocked down the Nichirin blade in his home. The sounds it made when it hit the ground told him it had not been used in years, but the sound of the metal scraping against the wooden confines of the scabbard were the same as any other trusty demon slaying blade. That told him that his grandfather, the previous owner of that blade, was a Demon Slayer.

To think that the household that generously sheltered him through the snowstorm hailed from a member of the Demon Slaying Corp. It was funny how fate works mysteriously.

But now was not the time to ponder such things. He had a job to complete...

...one that will be most difficult for the children accompanying him.

A man in western clothing. Illness suddenly growing worse to the point where he wouldn't allow anyone inside a dark room. A death occurring around the same time. Bloody stains on the bed.

It didn't take a police officer to figure out what this all meant.

He entered the house, immediately becoming disgruntled when he heard the sounds of bloodlust and hunger from within the house alongside flesh being torn apart. Once more, he was too late to protect yet another innocent soul from death and lamented his slowness. His hand went to his ax as Masaomi led him to his grandfather's chamber. Beside him, Yona grew more and more uncomfortable, feeling the malevolence in the air.

"This is Ojii-chan's room." Masaomi stopped and pointed to the double-sliding doors.

Gyomei's lips thinned. "Little ones." he advised. "Once I begin, you must flee from this place at once."

"Why?" Yona asked. Her eyes landed on his ax. "Are you...going to fight whatever is inside that room?"

"That I am."

"WhT?!" Masaomi cried. "B-But...But it's just Ojii-chan in there! He...he's sick! he wouldn't hurt a fly!"

Gyomei gently pushed Masaomi aside, and pulled the doors open. The second he did, Yona and Masaomi's face paled. Though Gyomei could not see the state of the room, the sound of sharp fangs tearing into flesh spoke volumes.

The room was splattered in crimson. The walls, the tatami mats, the ceiling and even the bed was soaked in blood. A rancid stench permeated the air, with the sole cause being the culprit. His body was thin and frail, thick veins popping out to the surface. His upper body was bare with only his yukata hiding away his nether regions, though much of his body was stained in red. His hair was frost white, utterly disheveled and untamed while his fingers continued to tear and grab at what looked to be a human body.

Masaomi blanced. "O-oh god... T-that yukata. That's Tuskume-chan's! Ojii-chan, what are you doing?!"

The elderly man stopped. "...Masaomi..." Yona shuddered. The village elder's voice was deep and throaty, as if there was something lodged in his throat. He slowly craned his head and saw his eyes bloodshot, pupils slanted and irises bloody red, his mouth containing bits of flesh and his mouth lined with fangs. "How many times must I tell you...not to enter my room?"

"O..." Masaomi whispered in horror. "Ojii-chan...?"

Gyomei stepped forward and slowly withdrew his weapon. "...as I thought. How lamentable. I had hoped my suspicions were wrong. You were weak from illness, and he offered you a chance to be rid of your sickness. In exchange for that cure, you would devour the people you were meant to protect. Truly pitiful. How I weep for your damned soul, elder."

"You..." the demon snarled as it turned around. "Who the hell are you?"

"I am to be your executioner. Remember this name as you enter the afterlife. Himejima, Gyomei." He pulled his arm back, ax over his shoulder. "**_Iwa no Kokyū, Shi no Kata: Ryūmongan・Sokusei_**!"

In the next moment, the house of the elder became a battlefield.

* * *

2B had seen witness to many battles, some lesser and others greater. She had seen the greatest war machines battling against YorHa and fell like the giants they were. She had seen countless mindless machines brought low by the blades of herself and her comrades. At one point, she had even battled against what she thought had been a magical being and barely came out of the experience alive and intact.

And yet, this world and time had so much to offer her.

_'That is...a demon?!'_

Despite being a frail old man, the village elder was moving and jumping around walls as nimbly as a YohRA droid. Add to it his savage behavior, and tenacity. It was hard for 2B to even follow him with her eyes.

And don't even get her started with Gyomei. His movements were practiced and all aimed with the intent to kill. His breathing was even and never skipping a beat. When the ax moved, so did the flail with enough power to shatter solid stone.

"W-what in the heck is going on?!" Masaomi, terrified and confused about the spectacle in front of him, demanded. "What happened to Ojii-chan?!"

2B didn't know how to answer that. She knew the village elder had been human, but clearly that was no longer the case. Something had happened to him and elicited a drastic change. What caused it, she didn't know.

All she knew was that they were in danger. They were children and standing right in front of a battle, one where even the slightest mistake would cost them their lives. Little wonder Gyomei had ordered them to flee the second things went to hell. Without a second thought, she grabbed Masaomi's hand and pulled him away, making a beeline for the outside world.

"L-let go, Yona! He's gonna kill Ojii-chan!"

2B glared at him. "That isn't your grandfather anymore!" she snapped back. "You know what you just saw! You honestly think a human being would eat another person?! Whatever that monster is, that is not your grandfather! Now, shut up and run!"

Masaomi looked like he wanted to argue, out of sheer desperation and denial given by his expression. But 2B was able to overpower him and drag him away from the scene of conflict. They had managed to get halfway across the path leading back to the village when the roof was suddenly obliterated into hundreds of pieces of wood and clay. The demon was soaring through the air and flailing and screaming before it came crashing back down, the snow softening its impact. It snarled as it scrambled back up to its feet and bared its fangs menacingly at Gyomei as he exited the house through the door, hand firmly wrapped around his ax. 2B wanted to continue watching the battle, but she was more concerned with fleeing this place before she and Masaomi were killed in the crossfire.

As she continued to run, 2B noticed something off. The blood red mist that clinged to the village elder was also in the village itself.

What did that mean...?

* * *

"_**Iwa no Kokyū, Ichi no Kata: Jamongan Sōkyoku**_!"

Both ax and flail danced with the chains as Gyomei attacked the demon with relentless intent. Despite being a newly born demon, the village elder was rather spry and was evading his attacks, but it was clear that it was wearing down. It couldn't dodge forever. Sooner or later, it was going to become tired. And when it did, he would be able to cleave its head from its shoulders.

The consecutive blows were evaded, but the ax tore straight through the demon's arm and severed it, creating a geyser of blood to spew out from its stump. The demon howled in pain and stumbled, rolling through the snow and staining its beautiful purity crimson before it came to a stop, holding its new stump and glaring at the Hashira in rage.

"You bastard! I'll kill you for that!"

"Aah, what foul words." Gyomei weeped. "You are truly a pitiful soul."

"Are you mocking me, you bastard?!"

"Confess your sins, elder. Why did you tear off Takeomi-san's face? You were practically tearing into your maid when we found you, yet the butcher's daughter only had her face torn off. Were you perhaps just starving?"

"What the hell are you talking about?! I had nothing to do with that!" the village elder sneered. Then it paused. Slowly, its fury gave way to amusement. "Gehihihi... Oooh, I get it. You have no idea, do you?"

Gyomei frowned. He did not like the tone the demon developed.

* * *

_'The mist, it's getting stronger...'_ 2B thought worriedly as she and Masaomi rushed to her home. It was probably the only safe place away from this madness. _'But why? The demon is all the way back there. What's going on?'_

The deeper they fled into the village, the thicker the bloody mist became. It should've been the opposite with the Demon far behind them. Something was wrong...and she didn't like it one bit.

"Y-Yona, slow down!" Masaomi begged. "I-I can't...!"

2B glanced behind her. His face was pale, breath visible in the cold air and sweat pouring down his face. They had been running for a while now, but the mist was worrisome. She hadn't stopped at all.

Eventually, she did come to a stop as they finally arrived at her home. She grew anxious when she saw that the mist was the thickest here. "W-we gotta go back." Masaomi begged. "L-look, whatever that thing was, it couldn't have been Ojii-chan! That big man is mistaken!"

"Are you serious?!" 2B couldn't believe the boy. "After what you saw, you still think it's a mistake?!"

"It has to be!" He argued. "Ojii-Chan would never hurt anyone!"

"You just saw him jump around the walls! He was standing over a corpse! I'm sorry, Masaomi, but you need to face the facts! Your grandfather is-" 2B was cut off when she heard a crash inside her home, followed by the sound of her father screaming. The mist grew heavy. Her eyes widened in panic. "Otou-sama." Leaving a spluttered and confused Masaomi behind, she quickly hurried into her home to find the source of the noise. "Otou-sama, what's-!"

"Y-Yona, stay back!"

2B came to a halt, eyes widening in fear.

The shrine holding her grandfather's picture was demolished and reduced to wooden scraps. Her father was sprawled against the floor, face pale and shoulder bloody. Standing over him was a towering man with ashen pale skin, the kimono covering his lower waist covered in tears. Compared to the village elder, this one had thicker muscle mass and his claws were sharper, left hand caked in freshly spewed blood. His hair was dark and fall to his waist while two horns protruded from his forehead, eyes dark blue with slits. A metal scythe was sticking out of his forearm, coated in flesh and attached to his own body as if it was produced biologically.

She now understood why the mist had not faded. It was because there was more than one.

"Another demon...!"

* * *

Gyomei's eyes widened in fear. "No..."

"I wasn't the one who killed Takeomi-chan, but she was my prey..." the village elder laughed sadistically. "I had no idea there was another demon running around in my village. I was pretty angry someone had the gall to step into my territory, but I ended up biting off more than I could chew. That's why I called Tsukume-chan for a snack."

'How could I have been so foolish?' the monk cursed his own foolishness. 'I should have anticipated that there was another demon lurking somewhere in the village, not just a singular beast.' He strained his ears and listened. Listened for the sound of bloodlust. His panic grew when he realized where the second demon was. 'No, not there!'

"Don't get distracted, you fool!"

The village elder leaped at him, taking advantage of Gyomei's moment of weakness. Then-

"_**Iwa no Kokyū, Ni no Kata: Tenmen Kudaki**_!"

Gyomei threw both his axe and spiked flail at the Demon in the form of a pincer attack. The Elder was caught off guard before he laughed.

"Really? Throwing your weapon at me?! How stupid are you?! I'll just avoid it!"

The demon tried to twirl its body midair to avoid the pincer attack. But Gyomei was faster. With a quick step, he smashed down on the chain. The sudden tautness caused the flail and axe to rebound and smash into his target. The spiked flail destroyed the elder's head while the axe cut through his neck.

Blood and gray matter flew through the air while the body soared right past Gyomei, crashing into the snowy mound right beside him. Soon enough, its body began to break down into ashes.

Usually, Gyomei would offer his prayers to the poor soul, but he had other things to worry about. He apologized to the deceased soul for his rudeness and hurried straight back towards Yona and Yukito's home.

* * *

"Y-Yona!"

2B gasped and choked for hair as her body slammed into the wall. She mustered back a glare of defiance at the monster before her, even as its grip over her throat tightened. Just a little more pressure, and her neck would snap. She knew full well how fragile her body was, and the demon knew it as well. It was toying with her, showing its dominance. It was trying to show her she was weak and it could kill her at any moment.

It made her its prisoner.

"Leave..." Yukito coughed up blood as he tried to stand, only to fall back on his knee. "Let my daughter go...!"

"Sorry, no can do." the demon smirked back at him as it revealed his pearly white fangs. "See, I need insurance. I know that one of those damned Demon Slayers is in this village. Can't exactly fight him head on."

2B spat in his face. "Go to hell."

"What a mouth! You kiss your mother with that tongue?" The demon's smile grew as it raised the arm with the scythe growing from its forearm. "If I were you, I'd choose my next words a bit more carefully, runt. Otherwise I might cut it off."

_'This is the worst possible situation.'_ 2B thought angrily._ 'If I had been in my old body, I would have killed this bastard with my bare hands. But I can't do a damned thing in this child's body!'_ She hated this feeling of uselessness. She was a fighter and protector, but now she had been reduced to this state. She glanced over at the sheathed katana, left abandoned on the floor. Her grandfather's sword, lying at her father's side._ 'If only I could grab hold of it...!'_

The demon chuckled as it looked at her, no doubt wondering what else it could do to intimidate before she saw its nose twitch and sniff the air. Its eyes widened in panic and quickly pulled her closer, neck now caught in between his forearm and bicep with the blade now dangerously close to her face. Gyomei barged into the house moments later, his weapon in hand.

"Stop right there, friend!" the demon warned. "You so much as twitch, and I slice this kid's face in half! Understand!"

Gyomei bared his teeth. "You fiend...!"

"Hey, I'm a demon! What'd you expect?" the demon cackled. "This is how we're gonna play this, see? I'm gonna walk out of here with the kid. You come after me? I chop off her pretty little head."

"You think I would trust the word of a demon?" Gyomei challenged.

"You don't have much choice, do you?"

2B glared at the demon. If it honestly thought she was just going to let this happen, it had another thing coming. "Himejima-san, do it." she called out. "Kill it."

Masaomi gaped at her. "W-what are you saying, Yona?!"

"Oi, brat! Shut the fuck up!"

The demon tightened its hold. She pushed back as much as she could. Her life was inconsequentual to the grand scheme of things. Was she scared of dying? As she was right now, yes. She was deathly afraid. 2B was never truly scared of dying as an android, but the human body had a finite lifespan. Sooner or later, she would die. She could not come back. The idea of dying like this would scare any child. But she couldn't allow this demon to escape. While it may be one of hundreds, if not maybe thousands, she could not allow this creature to escape and continue to kill any more people.

"Just do it! Hurry!" she urged him.

She could see on his face that Gyomei was hesitant. He was unsure what to do. If he was truly a Demon Slayer and someone who fought to protect mankind, he would do the right thing and kill this bastard and her along with it. This was his only chance. He may not have another opportunity like this ever again.

In the middle of this chaos and confusion, she had paid any attention to her father until his voice called out to her. "It's okay, Yona..."

2B turned her head. Her grandfather's katana was now in his hands, firmly against his hip with his thumb pressed up against the hilt and his other hand firmly holding the grip. His breathing was weak and labored, but it became even. Faintly, she could see what looked like a silvery mist flowing around him.

"Daddy will save you..." Yukito wheezed. "Just, hold on..."

"Yukito-san, do not do anything rash!" Gyomei advised. "That monster will kill your daughter!"

The demon sneered. "The blind monk has a point, you lowly human. How about you drop the bravado? Remember who's sword's just about ready to carve up your daughter's face?!"

"You...will not harm...my family."

Yukito sucked in a breath. His lungs expanded.

_'Forgive me, Tou-san. I must break my vow to you...and use the taboo.'_

"_**Tsuki no Kokyū, Hachi no Kata: Getsuryū Rinbi**_."

He withdrew the sword from its sheathe in a lightning-quick motion in a speed that no human should have been capable of normally. Not without enhancements. The cut in his body burned and screamed in protest to this action and would have otherwise hindered the movement, but at this moment, Yukito cared only about saving the life of his daughter. The only family she had left. He had put his whole body into this one single strike.

The second the tip of the blade left the scabbard, the technique was executed. To the untrained human eye, it looked as if he had only swung his sword at air. In truth, what Yukito had done was the result of years of practice and honing his technique.

To the eyes of those trained, a massive slash where the blade flew manifested. It's range was incredible, extending far beyond what the sword was normally able to reach. The gash in space resembled a crescent moon and cleanly severed the Demon's head from where he stood, leaving Yona unharmed. The demon's neck and lower jaw were entirely blown apart, leaving only the top half of his head. The body went slack and Yona dropped to the ground, coughing and hacking up a lung while the body collapsed on its back, blood spurting from the open wound.

_'What? What happened?'_ the demon thought as its body began to break down. _'I don't understand. He didn't even move. What was that technique he used just now? Since when...could...'_

That was the demon's last thought before it crumbled and turned to ash. Yukito, meanwhile, collapsed to the ground, the strain from his wound becoming too much to bear.

"Otou-sama!"

The young girl ran over to her fathers side. His skin turned pale and his breathing became shallow. He clutched the wound on his shoulder in an attempt to stop the bleeding, but it was a futile attempt. Looking at his state, 2B knew his fate. He was losing too much blood. Unless he received extensive medical treatment immediately, he wouldn't last the night. And there wasn't anyone in the village who had any medical skills to that degree.

Something inside 2B bubbled up to the surface. The same feelings she experienced when she had learned of her mother's passing.

"You fool..." 2B hissed. "Why would you do this?! Don't you realize what you've done to your body?! Why would you...!"

Yukito smiled weakly at her, eyes misty. Gently, he pressed a blood-caked hand against her cheek. "A man would do foolish things...to protect his daughter..."

"Masaomi-san, find help!" Gyomei barked as he quickly went over to Yukito's side, removing his coat and tearing off a piece in an attempt to bandage up the bleeding. "Wake the doctor if you have to!" Masaomi stood there, shell-shocked and unable to believe what had just happened. He raised his voice. "NOW!" The boy yelped and took off like a bullet, rushing out of the home and back out into the village. Gyomei quickly applied the makeshift bandage to his wounded shoulder. "Using a Breathing technique like that, in a state like this... It is a miracle you are even still alive right now!"

"_Haa_..._haa_...I know...never thought...I would...use it..." He panted.

"Please, save your breath." Gyomei urged. "Help is on the way!"

"Otou-sama, please..." 2B held his hand, hands shaking. She tried to push these emotions down and regain control, but she couldn't. They were too strong. Tears were openly pouring down her face. "You can't..."

"Forgive me, Yona..." Yukito said. The light in his eyes began to grow dimmer. "But it seems...I must leave you. Do not cry. Live...a beautiful life...just as Kiyo...hoped you would..."

His breath shook for a moment, then ceased. His eyes closed and his head lulled to the side. 2B's eyes widened, realizing what happened. She did not scream or cry out. All she could do was whimper and cling to his hand, his cold still hand, as she wept. Gyomei weeped as he clapped his hands and bowed his head, offering his prayers and safe travels for yet another parting soul.

* * *

The mood was entirely somber and depressing as the cloudy sky. The snow had ceased to fall, and the air seemed slightly warmer. It did little to ease 2B as she sat in the main room, tending to the broken remains of her grandfather's shrine. She did her best to try and fix it, but all she managed to do was get more splinters than any actual work done.

The house was depressingly empty. There wasn't anyone around, but that was a given. 2B was the sole remaining occupant of the house. Gyomei was currently handling the preparations for her father's funeral, having felt personally responsible for his death. 2B did not blame him for his death. If anything, it was her own fault for being so careless. She should have pieced together that there was another demon based on that red mist alone. It appeared around the home of the Village Elder, and it had appeared around the demon who invaded her home. The mist signified the presence of a demon, but she had been too slow.

Worse, she could do nothing. Had she had her old body-

_'No. I must not make anymore excuses.'_ 2B ceased that line of thought immediately, her tiny hands balling into fists._ 'I cannot keep going about what-ifs. I no longer have an android body. My body is that of flesh and blood now. I was unable to defend myself, nor was I able to protect my father. I was useless.'_ She bit her lower lip, the teeth nearly breaking through the skin. _'That cannot be allowed to continue.'_

"...Yona-san. I have returned." 2B looked over her shoulder and found Gyomei entering. "The preparations are complete. The village's doctor and smith are handling it as we speak." She nodded numbly, then returned to her work. She felt the man's blind gaze lingering on her for a moment, then heard him speak again. "...you will not attend?"

Her hands stopped. She pulled her hand back and stared at the matted floor underneath her. "...it is disgraceful, perhaps." she said softly. "I know I am expected to attend and see to it that his body is buried with all due honors...but I cannot. I will not see yet another family member buried. I..." She inhaled, then exhaled. Her emotions were rising to the surface again. "...if I am to look at his corpse, I will only remember my failure to protect him."

"Yona-san..." Gyomei approached her. Gently, he put his hand on her shoulder. It was rough, but at the same time gentle. "You did not fail in any matter. You are still a child. In that situation, there is little you could have-"

"Why did you not kill the demon when you had the chance?" 2B cut him midway, turning to face him. "You could have killed it at any moment."

Gyomei frowned. "Your life is a precious thing, Yona-san."

"The elder and that monster are not the only demons, are they? There are more out there in Japan. In the world, hunting down humans and feasting upon their flesh. Demon Slayers are those who hunt the demons and prevent them from causing casualties, isn't that correct?" Gyomei nodded. Her stare became bitter. "I know little about the Demon Slayer Corps, aside from what Otou-sama has told me, but from my point of view, you are no different from a soldier. Shouldn't the duty of the soldiers be to eliminate any and all threats, even if they must sacrifice the few to do so? If my death could prevent countless more at the hand of that demon, I would not hesitate to give it up."

"...is that how you truly feel, Yona-san?" 2B nodded. The man looked at her for a moment, then let out a deep, troubled sigh. "...what you are saying is not entirely wrong. In a sense, we Demon Slayers are soldiers, serving the people and to defend them from the demons. And in a manner of speaking, you would be right. That demon, who used you as a hostage, would have disposed of you the moment he no longer had a need of you. He would have killed more if given the opportunity. By your logic, it would have indeed seemed more appropriate to kill the demon and risk killing you as well."

"Then why?"

"Because as I said, your life is a precious thing." Gyomei repeated.

"My life is worthless when weighed against countless others!" She argued back. "Even if it was just one demon, killing him would've saved many more lives! If you had just killed me, Otou-san...Otou-san would be...!"

She cursed as she realized the emotions had resurfaced, stronger than before. She broke down, unable to quell them and sobbed. She didn't even notice Gyomei wrap his arms around her in a comforting hug. The man rubbed her back in an attempt to calm her down. Based on his actions, he was experienced in quelling children like this. 2B gradually felt calmer as the minutes passed.

"...forgive me. That was..."

"You simply spoke what you felt. There is no shame in speaking your personal feelings." Gyomei assured her. "I have said this before, but you are quite mature for one of your age. Most children would not think of sacrificing themselves, much less take other lives into consideration."

"It...it was the logical thing to do..." She answered.

"Even so, you are wiser than most your age. However, there is a difference between knowing right from wrong, and acting logically. Logically, your sacrifice to kill the demon would be the correct choice, and it would have indeed spared many lives in the process. However, I did not because it is the correct action. One cannot possibly know how everything will go. For example, what if your sacrifice proved unnecessary and we would have been able to kill the demon without you risking your life? What if you had died, but the demon managed to flee? One must take those scenarios and possibilities into account."

2B gave his answer some thought. He was not wrong. She had not given any thought to the alternative solutions or scenarios, just the ones that would have provided the best possible result. "...I see."

"Yona-san, if I may ask, what do you intend to do now?"

"Before all of this madness started, Otou-sama and Okaa-sama and I were going to see my uncle in Shanghai. I have already sent him a letter explaining what has transpired. Ideally, I hope he will be willing to take me in. If not, then Masaomi's parents have offered to look after me until they believe I am ready to look after myself."

Gyomei nodded. "I see. That does seem to be a good plan to have." He pulled himself up from the floor. "I must be leaving now. I pray you will live the good life your father wished."

"Of course." 2B stood up and bowed her head. "Thank you for all that you have done, Himejima-san. Before you go, there is something I wish to ask. Before he passed away...when you spoke with Otou-sama, you mentioned something about a breathing technique. What did you mean?"

"In a battle, even a newly-made demon will triumph over a skilled human, even if they possess a Nichirin blade. A sword forged of a very precious metal." Gyomei explained. "In order to give ourselves equal footing, we utilize a unique method known as the Concentrated Breathing. Each Demon Slayer utilizes a different form of Breathing technique. With the Breathing Technique, we can stop clotting wounds from severe injuries slow the circulation of blood in our bloodstream. This also bolsters our lung capacity and the amount of oxygen in our blood. With these techniques, we can strengthen our bodies to combat the demons. Of course, simply because we have such techniques does not mean we will succeed. We will still lose battles and perhaps even our limbs. And unlike the demons, we cannot regenerate such severe wounds."

"I see..."

Gyomei stared at 2B for a moment. Then he bowed his head. "By your leave, young one." She could tell there was more he wished to say, but it seemed that he chose to refrain. He left her home and vanished. Somehow, the young girl believed that this would not be the last time she would meet Gyomei Himejima. Not with what she had realized during her grief.

The demons in this world were a threat. She had been skeptical of their existence, but now she knew them and understood what they were. Monsters. Enemies of humanity. They were a threat who antagonized and killed. If left unchecked, they would no doubt run rampant. The Demon Slayers were warriors who combated these monsters and knew of the techniques and skills necessary to fight them. In this sense, they were indeed soldiers. Warriors whose task was to defend humanity from such monstrosities that dared to harm mankind.

In her world, 2B was created for the purpose of destroying the threats that dared to harm humanity. Of course, by the time she had been commissioned and brought online, humanity had already gone extinct. Thus, YorHa, known only to a select few, had been fighting a war that had long since been lost. Yet even so, 2B believed that, if there was still even a trace of humanity left in that world, then YorHa would fight to the very last to defend what remained of it. The safeguard and protection of the human race would always be, first and foremost, their ultimate goal.

2B returned to the shattered remains of the shrine, but rather than continue to fix it, she instead took hold of the katana. With the passing of her father, by birthright, this sword was now hers to own and wield. As she was now, she couldn't hope to use it efficiently. She needed this body to become stronger. Faster. Better. Capable of fighting the demons. Up until this point, she had lived the life of a human girl in Japan. Living the life that was expected of her. Battling the lingering feelings of what had once been the unit designated as 2B.

But after last night, she now understood. She no longer battled these conflicts, but instead welcomed them and joined them together. Once more, YoRHa No.2 Type B would take up arms.

She looked at the sword in her hands, and pulled. The glimmering steel reflected her eyes which glimmered with resolution.

"Glory...to mankind."

_It was time to return to the battlefield._

* * *

**AUTHOR'S NOTE**: Special thanks to Daemon of Wrath for his contribution in creating this opening chapter.

Fun fact, the only reason this was written was because an artist on DeviantArt by the name of dishwasher 1910 created artwork of 2B as a Demon Slayer. So blame him or her for this story.

Writing 2B's character was a bit difficult for me, namely because she was an android who is now living the life of a human being. And something tells me that, depending on the reception, I may expect some very harsh criticism for her character portrayal.

As for the Breathing technique 2B will learn, I ultimately decided to have her learn the Breath of the Moon. Spoilers to anyone who is not ahead in the manga, but the Breath of the Moon technique was created by the Upper Moon 1 Twelve Kizuki demon Kokushibo when he was human. This fanfic was written with the idea that Kokushibo had taught others how to use the Breath, but after he became a demon, the technique was widely criticized and seen as "taboo" as the creator became that which the Demon Slayer Corps fights. While there are still practitioners of the Breath of the Moon technique, there are considerably few in number. As in, there are only ten people who know how to use the technique, and how to pass it on to another.

That said, 2B will only have access to the first eight forms of the Breath of the Moon, as form nine and above were created by Kokushibo after his transformation into a demon. Naturally, though, when you compare the abilities of 2B to Kokushibo, even if she knows the same moves he does, Kokushibo has had centuries to hone and master his craft. She is a novice who is learning to master a technique that others see as taboo.

I'm still rather unsure were to take 2B's character and how she will change the events of the story, but I'm not aiming for anything too drastic. You can bet that a few deaths will be spared along the way, but aside from that, I am still planning out future events.

With that said, I hope you enjoy.


	2. 02

**DISCLAIMER**: I do not own Kimetsu no Yaiba or NieR. Both are properties of Koyoharu Gotōge and Yoko Taro respectively.

I do not own the cover art. All credits go to Deviant Artist dishwasher 1910.

* * *

**2B(a)DEMON SLAYER**

* * *

CHAPTER_02: Sun And Moon Will Forever Be Intertwined

* * *

_Ten Years Later..._

15-year-old Tanjiro Kamado had arrived at Fujikasade Mountain with anxiety and nervousness bundled together. Each of his footsteps was shaky, but not out of fear. Instead, he was dreading what he was to face. Having lost his whole family to a demon, and his sister turned into one herself, he had truly gone through hell. He had trained for two years in order to become a demon slayer in the hopes that his adventures would lead him to finding the means in which he could return her to normal. However, choosing this path meant risking his own life. A sacrifice he was more than willing to undertake if it meant he could restore Nezuko to normal.

As for why he arrived at Fujikasade, it was because the exam in which he may or may not become a demon slayer was taking place here. The Final Selection. His teacher had been pretty tight lipped about the whole exam, but what he did tell Tanjiro was that demons would be involved, hence why he was given a sword capable of killing a demon. If he succeeded in passing the exam, he would be given his own sword and uniform. That said, he couldn't afford to be careless even if the demons on the mountain were thought to be incredibly weak, having been starved and trapped.

The reason why they couldn't leave just happened to be the flowers that were dangling from tree branches, creating a beautiful purple florescent glow that captivated him as he passed under them, their scent sweet and soothing. The wisteria was a flower that was apparently both toxic and dangerous towards demons, enough so that they were repulsed by the smell. If they ate it, they'd be suffering from poisoning.

Every weakness and advantage demons had was pounded into his head, as were the sword techniques his teacher passed on to him in the two years he had been under his care. Now it was time to put that knowledge to the test.

After a minute or so of walking, Tanjiro arrived and stopped. Dozens of people, all carrying weapons similar to the one at his hip, were gathered in one place, each either confidant, terrified or anxious or all three at once. In particular was a boy with an ugly scar, his eyes scarily intense and fingers twitching. Another boy, hair blonde, looked scared out of his wits. Another was eerily calm, expression serene.

But the one who captivated him the most was the one who stood off to the side, wielding not one but two swords. One was fastened on her back while the second sat at her hip. She wore a black sleeveless kimono with a white sash around the waist, pouches dangling from the belt. She wore wooden sandals and knee-high black socks, a black hairband atop her snow-white hair. Oddly, the upper-half of her face was blindfolded, perhaps implying that she had been scarred.

Everyone present had a unique smell. The boy with the scar smelled like blood, but not like the demons. The terrified boy smelled like thunder clouds, and the serene girl smelled like wisteria. The blindfolded girl, though, had a more unique smell to her.

If he were to describe it, he thought she smelled like the moon...if that made any sense. There was no other way he could put it into words.

"Are they all here for the Final Selection...?"

He realized that many would be part of the Final Selection to become Demon Slayers. But he never would've thought he would run into people like them. Their scents were just so unique. It was unlike anything he's experienced before.

Although, his thoughts were focused on the moon-scented girl. Unlike everyone else, she carried two swords, one of them in a unique manner. Perhaps she was capable of dual wielding?

"Welcome."

Tanjiro was pulled from his musings, now taking notice of the two little girls that stood at the head of the crowd of people. Twins, both dressed in purple yukata with floral designs. While both had dark purple eyes, their hair color differed. One had black hair and the other had snow-white.

_'Who are they?'_ Tanjiro wondered curiously. They seemed awfully young to be attending the Final Selection. Actually, they couldn't be more than seven or eight.

"Everyone has been gathered." the girl with the black hair spoke. "Thank you all for attending this year's Final Selection. Fujikada mountain is home to many demons that have been captured."

"They cannot leave this mountain, as the wisteria here blooms at the foot of the mountain all year round." the girl with the white hair continued.

"However, there will no longer be anymore wisteria from this point forward. In other words, for the rest of your stay here, you will face the demons trapped here."

"Your task is to survive for seven days, and kill any demons you may encounter. Those who survive those seven days will have succeeded in completing the Final Selection."

The twins bowed and stepped aside, speaking in unison. "Let the Final Selection begin."

Those words set them off. Everyone rushed past them, either eager to find a hiding place and others looking forward to have their steel taste demon flesh and blood. Tanjiro was the last to follow them, trailing behind the rapidly dispersing group while keeping his nose sharp for any unusual smell. In his heart, he was hoping that there might be a demon here that could help give him the answers he was seeking. Surely, at least one of the demons here must know something about returning Nezuko to normal. And if not them, then maybe...

_"Listen, Tanjiro. In the past 400 years, there has only been one demon that is capable of creating other demons. The first demon, and the mortal enemy of all demon slayers. The name of that demon is...Kibutsuji Muzan."_

Muzan. The name of the first demon. The bastard who killed his family and turned Nezuko into a demon.

He gripped the hilt of his sword tightly, eyes burning and heart ablaze.

* * *

Two days passed. Two days with barely any rest or sleep. The mist in the air was thin, but the danger it represented did not lessen just because of that. She kept her wits sharp and her blade at the ready, ears listening for the faintest movement while her eyes looked past the cloth that bound them. To some, it looked like she was wearing a blindfold. In a way, they would be correct. The blindfold had no functions beside hiding her sight from her, but it served a purpose. Using one's eyes was not always the only way to determine where a potential threat may come. And while her eyes may be obstructed, that didn't mean she could not see what was in front of her. Her ears did not pick up the faintest sounds like echolocation and create a "map" of her surroundings.

Instead, she had used what Isshin had taught her. To see the world as it must be seen.

_"Your eyes betray you."_ Isshin told her. _"They betray the world, too. What you see on the surface is how the world should look, but it is now how it actually should. Do not let your sight show you what is and is not in front of you. Instead, use the eyes in your mind."_

And so, she did. And when her hidden eyes opened, her sword was drawn.

"_**Tsuki no Kokyū, Ichi no kata: Yamizuki - Yoi no Miya.**_"

Her swing was a blur. From a single stroke came a myriad of smaller, crescent slashes that shredded the approaching demon within range. The twisted soul had no time to realize it was dead until it's head was severed while its body was minced to pieces.

As its body began to break apart into ashes, 2B slid the blade back into its sheathe. The katana fell inside with a 'click.' With another demon slain, she continued her assigned task. In the short time that passed, she encountered only two or three others who stubbornly chose to fight by themselves instead of finding a group. The odds of survival were much higher if people trusted one another to survive, especially in the present circumstances.

Still, she doubted they would have much trouble unless they got cocky. Compared to the demons Isshin threw her against in Shanghai, the ones trapped here on the mountain were pitifully weak. That was to be expected, given they were starved and have only eaten a small number of people - the fates of other individuals who took the test and died at their hands notwithstanding.

And yet, she could see it. A pungent, almost violent air that burned. Somewhere within the bloody mist her eyes could perceive, a portion of it was thick.

There was a powerful demon lurking here in the mountain. Possibly having devoured many demon slayers, and perhaps even members of its own kind. Her uncle did mention to her that there were recorded cases of demons committing cannibalism, though they were quite rare. As to why a demon would eat another demon, the theory was that the demon committing cannibalism would grow stronger by feasting upon the flesh of another demon and undergo a mutation. Even develop a Blood Art they never had previously. Of course, there were no cases of there being demons with two Blood Arts, so it was more likely that the cannibal developed a Blood Art of their own, or perhaps took it from its victim.

At any rate, 2B's goal was to survive for seven days and kill any demon who got in her way. There was no reason for her to kill something that could prove potentially dangerous. She could not afford to take any risks.

However, if the demon was threatening another one of the humans here, then she would intervene. To defend humanity was her task, after all.

As she continued on her way, moving up closer towards the base of the mountain, she suddenly stopped when she saw the mist shift subtly. Another demon was approaching. Her thumb pressed up against the hilt of her katana, ready to slay it the second it emerged. She waited patiently, foot rooted to the ground while keeping her body tense. Her breathing changed, smooth and calm while her body grew tense.

Twelve seconds passed before the demon emerged. Just as she was about to strike it in a single blow, something bizarre happened.

Namely, the sight of what looked like a man with a boar's head headbutting the demon straight into its abdomen and sending it flying.

"Gyahahahahahaha! Pig Assault! Pig Assault! Gyahahahah!"

2B's eyes blinked underneath the blindfold. The head of a boar was a mask as she did not see the lips move at all. The fur was also wrong, hairs too thick and the eyes not made of thin membrane and flesh. The man's body was muscular and well-toned, implying good physical training. His stance was completely full of holes, but the way he gripped his swords showed that he was no stranger to combat. The mist surrounding his body was brown and wild, akin to a beast ready for battle.

Before 2B could properly assess what was happening, the pig-masked man let out another battle cry and charged after the demon who realized it was in danger and fled. She watched the two vanish further into the forest, too dumbfounded to chase after them.

Instead, she could only make an observation. "The humans of the Taishō period are strange indeed."

* * *

On the third day, Tanjiro encountered both a great danger and his first real test as an up-and-coming demon slayer. He had finished slaying two demons and offered his respects, hoping they would be find a happy life in the next world when he felt a disgusting smell suddenly invade his nostrils. Not a second later, a shrill scream pierced the air and alerted him of the presence of yet another demon, chasing after one of the applicants of the Final Selection.

The source behind the nauseating smell was perhaps the most warped demon he saw. He couldn't make an actual body, for every inch of it was covered in thick burly arms. The only visible portion of its body that he could see was its head, which was also wrapped in arms and bearing golden eyes with cross-shaped slits. Its skin was dark green, veins throbbing underneath its flesh.

Worst of all was the thick sent of blood. Tanjiro couldn't help but tremble.

_'How many people has this monster eaten?!'_

"D-dammit!" the demon's target cursed as he scrambled to escape. "W-why is there a mutant type here?! We weren't told about this!"

The demon let out a low chuckle before it raised what Tanjiro assumed was its actual left arm. It extended and reached out, grabbing the applicant by its angle. The red-haired boy didn't need anymore time to think and let his body move on its own. He sucked in a breath and felt his blood explode in his veins, muscles becoming thick.

"_**Mizu no Kokyū, Ni no Kata: Mizu Guruma**_!"

His body spun forward while the blade carved through the air seamlessly as if it as treading through water. He sliced straight through the appendage easily. The grip slackened and the applicant was released, dropping to the ground with a yelp. The demon was surprised by Tanjiro's sudden appearance, but didn't seem too angry or shocked by the loss of its limb.

Immediately afterwards, Tanjiro put himself between the applicant and the demon, sword raised. _'This one is completely out of my league. There's no way I can take it on without risking serious injury. Even so, if I can just buy him enough time to escape, then...!'_

"**...kekekekeke. I've found another fox**." Tanjiro blinked when he saw the demon laugh. For some reason, its eyes fell on the mask his teacher, Urokodaki, had given him when he set off for the Final Selection. "**Tell me, fox... What year is it now?"**

Tanjiro was surprised a Demon would ask such a question. But he steeled himself and responded. "It's the Taishō Period now!"

**"Taishō...?"** The Demon rolled its eyes in contemplation. After a few moment, its eyes snapped open as it roared. Its body thrashed around, its multiple arms flailing about, some of them clawing deep into its own flesh. Tanjiro and the boy he saved could only look on in morbid fascination. **"Holy shit! Time has passed into a new period?! Again! Again while I've been held prisoner in this wretched place?!" **His arms trembled as if they could shoot out at any time. **"Damn you, Urokodaki! Damn you Urokodaki!"**

Tanjiro's eyes widened. "Y-you know Urokodaki-sensei?!"

**"Know him?! Of course I know that bastard!"** the demon snarled, eyes full of hate. **"He's the bastard who threw me onto this mountain! I could never forget that bastard! I remember him well, ever since the day we met 47 years ago during the Keio Era!"**

The red-haired boy choked. The boy behind him stared in shock. "That can't be right! There are no demons who've lived for that long here on this mountain! If there were, they'd have been killed either by themselves or by other Demon Slayers! That can't be true!"

The demon laughed, its hate for Urokodaki now forgotten. **"Oh, but I am here. I've been on this mountain for four decades now."** His eyes once again fell on Tanjiro, or more specifically the fox mask he was wearing. **"I've devoured fifty humans in the time I've been trapped in this god-forsaken place."** Tanjiro froze. He remembered Urokodaki's lecture about how powerful demons could become based on the number of humans they devoured. It certainly explained the horrid smell. And more importantly, the threat that was standing in front of him. **"Let's see... Twelve, thirteen, and the last one was... Yes, you little boy. You'll be the fourteenth fox I will have eaten."**

"Fourteenth?" Tanjiro narrowed his eyes. "What do you mean?"

**"You got that mask from Urokodaki, riiight?**" the demon pointed to the item in question. **"I remembered the first person I ate who wore that mask as he cried for Urokodaki's forgiveness for failing some kind of test. Then came another little fox I found, who muttered those same words. That's when I realized anyone who was wearing fox masks were all of Urokodaki's cute little students."** Though Tanjiro couldn't see it beneath those arms, he was certain the demon was smiling wickedly. **"And I've made sure to eat all of the cute little foxes who've crossed my path. I remember some of the more important ones, like that strong kid with the scar or that little girl that tagged along with him."**

His blood went cold. His heart dropped. The description it just gave, he knew immediately who he was talking about. His other teachers, besides Urokodaki. The two who helped him cut straight through that boulder with all of his might.

Sabito and Makomo. Two others who wore the same fox mask he did.

**"I made sure to remember the distinct designs of the mask, so I knew which ones were Urokodaki's students. I think one of them called it a mask that prevents disaster, right? It's a shame that all it did was lead them to their deaths."** The demon laughed once more, this time full of bitter anger. **"It's almost like Urokodaki sent them to their deaths. Oh, I wish you could have been there. That little girl with that strong boy got so angry she tried to kill me, but her movements became so rigid. She made it so easy for me to tear off her arms and legs. Kekekekekeke!"**

Though he was usually as calm as the ocean waves, something about the way the demon gloated about killing Makomo caused something in him to snap. A burning scream ripped from his throat as he charged straight at the demon wick reckless abandon. In response, the demon shot several arms straight at him. Each arm was severed with ease, but Tanjiro's breathing became erratic. The strength in his body slowly began to dip.

_"Calm yourself, Tanjiro."_ a familiar voice whispered in his ear, but couldn't break through the haze of hate that was clouding Tanjiro's mind. _"Your breathing is all over the place. Stop thinking about what happened to us!"_

Tanjiro couldn't hear those words in time, for in his recklessness he was punished as two fists suddenly crashed straight into his ribs. He felt bones crack from the impact and the wind knocked from his sails before he was sent flying, landing face-first into the ground. He rolled away from the demon until he came to a stop, his mind left in a daze. The whole world was spinning. His stomach was lurching uncomfortably, and his side was flaring in pain. He knew for certain that his ribs were cracked, but he couldn't afford to let it cloud his mind. He had made a mistake, and now he was paying for it.

Even so, he had to fight.

With a wicked laugh, eager to see yet another student of Urokodaki dead and in his belly, the demon sent out another wave of arms towards Tanjiro. Still dazed and recovering, he had little to no time at all to defend himself, much raise his sword.

At that moment, however, someone intervened as a familiar scent, akin to moon-filled night, entered his nostrils.

"_**Tsuki no Kokyū, Hachi no Kata: Getsuryū Rinbi**_."

A sword cut through the air, but the blade itself never touched the demon's arms. Instead, a crescent wave made entirely of air did the dirty work and easily sliced through the arms.

**"What the hell?!"**

Tanjiro was just as surprised. What was that technique? Who did that?

"Calm yourself." a soothing voice admonished him. The scarred boy blinked. Standing between him and the Demon was the blindfolded girl he saw at the entrance. "Your breathing is erratic. Take a moment to calm down. You can't fight if your breath is uneven."

Tanjiro stared at her for a moment, then nodded. "R-right. Thank you."

* * *

2B froze. The second the boy with the crimson aura spoke, his face overlapped with someone else's.

This moment, it reminded her of something. No, it reminded her of someone. Their facial features were a little similar, and their voices were the same, but whereas the scarred boy had a tone of innocence and gentleness, 9S was curious with a hidden biting edge to it. They were two different people, much less two different beings. One was human, and the other was an android.

She took a quick breath to calm herself down and remove such unnecessary thoughts, instead focusing on the demon in front of her. She had hoped she didn't need to get involved, but she saw someone running away from the same direction where the intense portion of the mist emanated, where it was quickly overwhelming the mist that surrounded the scarred boy. The mist surrounding him was odd, dyed the color of pure flame but danced around him like waves in the ocean.

At any rate, 2B found herself engaging the demon. True to her expectations, its form was radically different from the ones she encountered previously, though based on what she just saw it didn't appear to possess any form of Blood Art. How many demons and humans must it have devoured in order to obtain such an appearance, much less developed such grotesque abilities?

She looked at the stumps of the arms she severed, only to find that they had already regenerated. Its regenerative ability was amazing. It took maybe four or five seconds for it to repair the damage it sustained.

That would make killing it difficult. Of course, there was a more effective way to kill the demon. That was, naturally, to sever its head from its neck. Getting up close, however, would be difficult. Its raw strength and ability to regenerate, much less its multitude of hands, would make it difficult for them to get in close enough to deliver the killing blow, as well as escape.

"Can you still fight?" 2B asked the scarred boy.

He nodded. "Y-yes, though I think that last attack cracked a few of my ribs."

"Power through it. Get ready." She drew her sword from its sheathe. "He's coming."

**"You damn bitch!"** The Demon snarled at 2B, his hands twitching madly. **"That fucking hurt! I'll kill you! I'll rip off all your limbs and eat them one by one!"**

2B only looked at the demon for a moment before she and the scarred boy both moved forward. At that moment, the demon sent out several arms to intercept them. With fluid movements akin to a water stream, the scarred boy cut through each arm. His advance was halted much like herself, though in contrast to his fluid movements she moved much faster. Though she was still nowhere close to the level she was at in her previous life, she was still fast on her feet and just as capable with her sword. However, she could not withdrew her other blade.

Not yet.

_'Keheheheheh. That's it, just focus on what's in front of you!'_ the demon thought with a sneer as one of its arms burrowed its way underground, slithering towards its target. _'Even if you two fight together, I've already won!'_

The scarred boy spun in a full circle, slicing off several arms before he stopped. He glanced at the ground, nose twitching, then leaped off the ground. Just in time, as he evaded an arm that exploded from up out of the ground, fingers open with the intent of breaking all of his bones at once the second he was in his grasp. 2B clicked her tongue as she spun on her heel, dismembering the limb before performing two backflips, evading two more arms and chopping them off in the process.

The demon was stunned by the scarred boy's ability. To think he'd sense his arm coming up from below to grab him! But that surprise gave way to glee, for even if he could evade that attack, there was no way he could defend himself in mid-air. He capitalized on the young boy's foolishness and sent an arm forward, intent on breaking his neck. The boy glared as he reared his back, and to the shock of both present, rammed his forehead straight into the incoming fist. Even more shocking was that the force behind the headbutt was enough to divert the arm's direction.

_'He diverted that attack with a headbutt?!'_ 2B stared in shock. _'How thick is his skull for him to accomplish that and not become disoriented?!'_

Taking advantage of the momentum created by his headbutt, the scarred boy landed on the demon's arm and charged, blade poised to sever its head. The demon, in one last act of desperation, sent several arms towards him. 2B would not allow that to happen, not even for a moment. She sucked in a breath and let it spread through her body. She launched herself forward, her empty hand reaching for the blade on her back. The sole memento she had of her father and her grandfather.

"_**Tsuki no Kokyū, San no Kata**_-"

The blade was withdrawn from its sheathe. Twin swords in hand, 2B let them roar with all their might. For a brief moment, the light of a full moon reflected on the blades. The demon saw this and, for a brief moment, saw a terrifying figure behind her. The man who was with the same person who made it. Though he was but an image, faint and hallucinate, there was no stopping the terror that echoed throughout its very being as six hellish eyes glared down at it.

"-_**Enkizuki - Tsugari**_!"

The blades were swung and created twin razor-sharp arcs of wind that flew straight at its arms. However, in mid-flight smaller crescent arcs formed around them and scattered. Within seconds, the demon's last ditch effort to kill Urokodaki's student were chopped to pieces. Some of the arcs even sliced away at his own body, creating small but deep cuts.

_'N-no way... She destroyed all my arms in seconds. Shit. I can't regenerate my arms in time.'_ The scarred boy drew closer, his blade ready to deliver the killing blow. _'But, even if I die, I can still take this kid with me. Not even that kid with the scar could cut through my neck. Once he fails, I'll have just enough time to kill in and crush his head in!'_

And yet, despite those words, the demon could only feel unadulterated fear as the boy neared. Just like before, when 2B had cut apart his arms, he saw an image overlap with his quarry. Instead of a boy with fiery red hair and a scar, all he saw was that dreadful visage of a man leaping at him, blade raised and Tengu mask shielding his face.

"Uro...kodaki...!"

"_**Mizu no Kokyū, Ichi no Kata: Minamo Giri**_!"

Streams of water flowed across the blade as Tanjiro swung horizontally. Blade met reinforced neck.

Blade emerged victorious. The forged edge cleaved through the Demon's neck like a hot knife through butter. The Demon did not realize his demise until he blinked. Once. Twice. His view of the world tumbled and turned as he saw his body collapse right next to him. 2B let out a sigh as she slid her swords back into their respective sheathes. Similarly, the boy had done the same. Even so, the former did not relax. They couldn't afford to just yet. For all they knew, the demon must still have some tricks up their sleeve. Not even the lessening of the bloody mist around the dying mist made her relax. She looked at the demon's corpse as its body gradually began to break down into ash. Looking at its head, she saw that its golden eyes were locked on to the scarred boy, glaring at him with hate. Not that she would have expected anything less from such a miserable and despicable creature.

She looked at the scarred boy, intent on asking him if he was alright, when she saw the look in his eyes as he turned to look back at the demon. Instead of arrogance over having prevailed, smugness for having defeated an opponent stronger than he, relief that he had survived, she instead only found sadness and pity. Both emotions were directed at the demon's decaying head. But that didn't make any sense to her. Why would he feel pity for a demon? The demon itself seemed to share in her feelings, as its hate was discarded and just stared at the boy, unsure of what to make of him.

A motion caught her attention. The body moved, but only slightly. It was obvious the demon no longer had any strength left to enact a final attack. All it managed to do was open up its hand. The scarred boy looked back at it, then glanced once more at the decapitated head before he did something that confused her even more. He wrapped his hands around the demon's own hand.

"Kami-sama, please. Never let this person become a demon again when he reincarnates..."

The demon stared at him, eyes wide as tears spilled down its face. That was the last look it had before its head, as well as the rest of its body, fell apart into ashes. The boy looked down sadly at the pile of remains, still looking pitifully at it. 2B did not understand why he was doing that. Why was he pitying that monster?

"Why did you do that?" she found herself asking. "Surely, you must have known. That demon devoured many people. It did not deserve kindness."

The boy looked at her with a sad smile. His answer surprised her. "...because even he was a monster, he was human once."

2B stared at him for a moment, then shook her head. He looked to be fine in spite of his injuries. Surely by now, the number of demons on the mountain must have thinned. And with such a threat now eliminated, there would be less risks involved. She turned on her heel and left, feeling his eyes on her back.

She sighed. "Even after all this time, I still do not understand humans."

* * *

Four days went by after that fateful encounter. The sun had already begun to set when Tanjiro had reached the base of the mountain. When he was greeted with all the others who had survived the Final Selection, he couldn't help but look in shock.

"O-only five?!"

The serene-looking girl, the blonde boy, the boy with the ugly scar, the girl with the blindfold and himself. That was all that stood before the twins. Compared to the dozens of people who were here previously, he couldn't help but feel dismayed. How could this be possible? Surely, more must have passed. Maybe some just didn't make the cut and realized they were in over their heads or something? Or what if they had...

His mind drifted back to the third day, when he saved an applicant from the demon who killed Urokodaki's students and his predecessors. Had that person not survived after all?

His heart ached. He bit his lip, fingers digging into his palms. This was not fair whatsoever. Why had only the five here managed to survive? There must have been stronger people among them, right?

"Welcome back." the girl with white hair greeted as she and her sister bowed.

"You have returned, alive and well. Congratulations."

"What do we do now?" the boy with the scar asked rather rudely. "What about our swords?"

His question went ignored. "First, you must pay the cost of your uniform, then have your measurements taken."

"Afterwards, your rank will be engraved in your uniform. There are ten ranks."

"Mizunoto. Mizunoe. Kanoto. Kanoe. Tsuchinoto. Tsuchinoe. Hinoto. Hinoe. Kinoto. Kinoe. Currently, you are all Mizunoto, the lowest rank."

"What about our swords?" the boy with the scar asked again, this time sounding more annoyed than anything.

"You will choose a piece of Tamahagane Ore." the girl with white hair turned to him. "The sword will be completed within ten to fifteen days. Additionally, you will be accompanied by a Kasugaigarasu from today forward."

She clapped her hands. To Tanjiro's surprise, four crows and a sparrow emerged from the trees, flocking to their side. One perched itself atop his shoulder and let out a squawk of pride. The blonde-haired boy stared at the sparrow in confusion while glancing at the rest of the crows, wondering if there must have been some kind of mistake. The boy with the scar, however, smacked his crow away when it attempted to perch itself to his shoulder.

"I don't care about a stupid crow!" He stomped up to the girl with the white hair and grabbed a fistful of her hair, pulling her up to his face much to the shock and aghast of the others. "What I want is the demon slayer's sword! The Nichirin Blade! Give it to me now!"

"That is enough." the girl with the blindfold appeared beside the scarred boy and gently pried his arm away from the girl's head. "They just explained that we will receive our swords within two weeks. Please be patient."

"I don't care!" He pried his arm out of her grasp. "I want the sword now! How else would I kill Demons without it?!"

"I understand. But they are simply explaining our duty as Demon Slayers." She stood her ground. "It would help if we waited for them to explain everything." The boy growled and looked ready to throttle her. Tanjiro looked on with worry and was ready to intervene, but the blindfolded girl's hand went to her sword. "Cease and desist this action immediately." she advised. "Any further, and I will use force. Choose wisely."

The boy glowered but realized he was outmatched either way. He reluctantly backed away and rubbed his arm.

"Are you finished?" the girl with black hair asked. "If so, please go over there." She gestured to the table behind them. On the table was an assortment of chunks of metal. "The alloy you choose will become the sword that you will wield to defend yourself and destroy the demons. You must choose which piece will become your sword."

_'They are so many.'_ Tanjiro looked at the chunks of metal, unsure which to pick. _'I don't know anything about these metals, and they all small the same. Does it matter which piece we pick? How is it going to affect our swords?'_ In the end, he still had no answer. Instead, all he could do was trust his instincts.

His hand reached out and grabbed hold of the piece of his choice. The rest soon followed.

* * *

The five newest members of the Demon Slayers Corps had dispersed and left Fujikasade Mountain, no doubt returning to their homes and rest, then train and await for the arrival of their swords. As the twins explained to them, once they had both their uniform and sword, they would begin their missions as demon slayers immediately.

Before 2B could leave for her temporary residence, however, one of the twins had walked up to her. "Please, wait a moment." The former android looked at the small girl in confusion. "Our otou-sama would wish to speak with you, Tsukiko Yona-sama."

"Your otou-sama?"

Why would this girl's parent wish to speak with her? Moreover, who was her father anyhow? Now that she thought about it, she still did not know the identities of the girls. Considering that they were supervising the Final Selection, and given that the Demon Slayer Corps trusted them enough to oversee it, they must hold some kind of sway within the organization. The first such individuals that came to mind were the Hashira - the strongest demons slayers within the organization that answered directly to the leader of the Demon Slayer Corps, Kagaya Ubuyashiki.

Either way, 2B saw that she was really in no position to refuse. It wouldn't do well for her to deny such a request, regardless of who their parent was. She gave a small nod and followed the girl. She rejoined with her twin sister, and the three made their way down the mountain. A small carriage was waiting for them, where a man stood guard waiting for them. As soon as she saw him, 2B grew tense.

A heavy mist surrounded him, thick and violent like a storm. His body had numerous scars, the most prominent being the ones on his chest and face. His white hair was wild and his eyes looked manic, yet there was clearly a sense of clarity in them. He wore the uniform of the Demon Slayers, but over it was a white haori, implying that he was of a higher rank than she was. At his hip was his Nichirin sword.

The man's eyes zeroed in on her. "You're the girl. Yona, right?"

"Yes." 2B replied. So he already knew about her? And from his tone of voice, he did not seem to have a good view of her. "And you are?"

"The name's Sanemi. The Wind Hashira." He grunted. "Oyakata-sama requests your presence." He opened the carriage door. "Get in."

She was stunned. A Hashira was here? She glanced at the girls beside her, who smiled and thanked Sanemi. In contrast to his attitude towards her, Sanemi smiled gratefully back at them with all due respect. Then his previous words registered.

Why did the leader of the Demon Slayers want to speak with her?

* * *

It took three days for the carriage to arrive at the estate where Kagaya Ubuyashiki resided. And as 2B expected, it was as large as it was beautiful. It wasn't the size of a lord's castle, but the grounds it sat on was enough to fill the field of a common lord's territory. She had half a mind to wonder what use such a large facility would be to a man, aside from a massive statement and testament to his influence.

She did not have time to stare at the mansion's exterior for long as she was soon ushered inside and led into what she assumed was the main complex. Sanemi led her down the halls with his back facing her. During the whole journey, he rarely ever spoke to her, and whenever he did, he made it clear that he did not appreciate her presence for whatever reason.

She had a good idea why. Isshin had told her that not many in the Demon Slayer Corps would appreciate her using the Breath of the Moon, and obviously Sanemi knew she was a practitioner of the style. How he knew that, she had no idea.

An idea came to mind as they walked. Was it possible that Ubuyashiki wanted to speak with her regarding her usage of the style? Would he shun her or remove her from the organization based on that fact? She doubted this was the case, seeing as how there were still people who used it, albeit very few. According to Isshin, following the passing of her father and her taking up the style as her own, there was only a meager handful of people who still utilized the Breath of the Moon. Some of those users were still active members of the Demon Slayer Corps, so the idea that Ubuyashiki would ostracize her simply for that fact alone was not possible.

That only raised further questions of course, yet she knew she would soon discover the answer soon enough. After a minute or so of walking through the halls of the estate and its main complex, Sanemi stopped in front of a pair of elaborate doors with vibrant designs, cherry blossoms and koi fish printed on the front.

"Oyakata-sama." Sanemi kneeled in front of the door. "I've brought Tsukiko Yona, as requested."

"Thank you, Sanemi." a gentle voice called out from beyond the door. "Please, send her in."

Sanemi turned his head to 2B. "Be sure to give your proper respects, girl." he warned. "Disrespect the master, and I will see to it you pay for it."

"Understood." 2B replied calmly, unfazed by his hostility. She took a moment to compose herself, then opened the door and stepped inside.

As soon as she was within the room, the door closed behind her. But that small fact did not bother her for her attention was focused on the person before her. In contrast to her initial thoughts of the Head of the Demon Slayer Corp. being a man in his later years in life, Kagaya Ubuyashiki was a man no older than his mid twenties. He was dressed in a black yukata with a white haori with flame motifs on the edge. His hair was black and cut around his neck. But what stood out to 2B the most was his face. While he was definitely attractive, her focus was not his physical beauty, but the fact that the upper half of his face was scarred over. The flesh was discolored and looked as if it was rotting. His eyes were blank and glassy, indicating he was blind.

The mist surrounding him was like a rainbow, ever changing and beautiful. It also carried a strange scent, putting her at ease for the first time in what seemed like years. The idea that she would face combat seemed so far away. Yet that odd feeling of peace came to an abrupt end when she realized what was happening and reclaimed her edge. She could not afford to be lax or comfortable. She must remain vigilant, even in the presence of someone like this.

Kagaya Ubuyashiki did not address her immediately. He sipped the teacup in his hands, savoring the taste of the drink before he gently sit down on the mat.

"...I believe that this is the first time we've met, is it not? Tsukiko Yona?"

"I believe so." 2B replied curtly.

The man smiled kindly. "Please, take a seat." Though hesitant at first, she obeyed and approached. She gently set herself down in front of her, knees pressed against the tatami mat. "I am sure there must be many questions you have, such as I why I called for you out of everyone who succeeded in the Final Selection. But before I get into that, I must ask you. How is Isshin doing these days?"

2B blinked beneath her blindfold. "You...know of my Ojii-sama?"

"I remember the names of every one of my demon slayers, whether they are still under my employ, dead or retired." Kagaya answered. "Isshin was one of my favorites, truth be told. In the admittedly short time I've spent as the 97th leader of the Demon Slayer Corps, I've never met a man so devoted to the cause. To his allies, he treasured them as if he were family. To the demons, he may as well have been the shinigami himself. I whole-heartedly believe he was worthy of the position of a Hashira, but he ultimately declined. He was rather humble then as well."

2B smiled slightly. "Yes, he is. Though I'm afraid he has become quite the grouch in his old age, as well as a stern teacher."

"I imagine so." Kagaya chuckled. "May I offer you some tea, Yona?"

"No. I am fine. Thank you for offering."

The man nodded. "Very well. I suppose we should move past the pleasantries and get to the heart of the matter, then. I imagine you must be wondering why it is I've asked you to come here."

"I have a good guess as to why. It is because I practice the Breath of the Moon."

Kagaya gave a strange smile before he looked to the side. In open view, there was a beautiful stone garden with a small pond surrounded by rocks. The sky was painted clear blue with few clouds above. Combined with the peaceful nature that surrounded Kagaya Ubuyashiki, 2B wondered if this could be called a scene in heaven. "The Breath of the Moon was among the many styles developed by the first Demon Slayers." he said. "Much of our records pertaining to that time have been lost, including the identity of its creator as well as the lost style once used by the very first Demon Slayer himself. However, what little we do know is that the man who created the Breath of the Moon betrayed his comrades and students by becoming a demon, falling sway to Kibutsuji Muzan."

"And as a result, those who practiced the Breath of the Moon became ostracized." 2B continued sadly. The image of her father flashed in her mind, dying and suffering from his wound with sword in hand. "Though they fought for the sake of defending mankind from the demons, their comrades were angry that they would continue to use techniques that were made by a demon."

"And the results of such alienation can still be felt. Including yourself, there are only ten people in the world who still use the Breath of the Moon." Kagaya looked back at her. "Tell me. Why did you decide to choose the Breath of the Moon?"

At this, 2B fell silent as she looked to the stone garden. Memories from years ago flashed by in her mind, back to the days when she first began her path to once again defending humanity from those who dared to wish them harm.

* * *

_Nine Years Ago..._

Shanghai.

Compared to Japan, which had was still in its infancy regarding its subtle changes towards westernization cultures, one of the municipal cities of China was well in its way. The streets became paved with cobblestone and railroad tracks. Buildings that were once made of tiled roofs and mud huts became replaced with bricks and stone. Steel poles were lined against paths next to the street made from concrete, bulbs attached to the end of each pole. Everyone, sans for a few odd individuals, were wearing western clothing such as suits and dresses.

The ship docked and set its ramp down, allowing its passengers to disembark. Among those passengers was a little girl, 11-year-old with icy blue eyes and snow-white hair. She was of Asian descent, wearing a small white yukata while carrying a wooden box in her tiny arms. Though she had the appearance of a child, her eyes told a different side.

The presence of a young girl with seemingly no one there at her side was enough to raise some concerns. Many questioned if she was an orphan or if she was lost. Others believed that the girl was a runaway, escaping a harsh life in exchange for a better one. However, there were some who held the girl with some hostility when they recognized she was of Japanese heritage.

The relationship between China and Japan has always been strained. Several events in the past had left both countries viewing each other with caution, though the inclusion of western culture and trading was perhaps the biggest cause of concern as Japan slowly and forcefully began to push its change to westernization onto them. One account said that Japan viewed China as an "antique" culture. This was but one of the many reasons why China and Japan hated each other, and it would surely not be the last. And as one might imagine, a person of Japanese heritage was usually met with hostility or suspicion.

That same treatment was extended towards children as well, though notably there were less people who treated her with such open anger. After all, she was a child. Japanese she may be, it was not as if she could help where she was born.

She was here for one reason and one reason only; to find her remaining family. Her father had planned to take her and travel to Shanghai for a new start after her mother's death.

However, due to the demon attack and her father's unfortunate demise, plans were changed. Seeing as her only family was in Shanghai, she made her decision. Certainly she could've remained in Japan by living with one of her neighbors, but none of them could offer what she sought. With demons on the prowl, she needed a means to fight. To fight like her father had in that one, brief moment. Surely her uncle had the answers.

Admittedly, it was a shot in the dark doing this. She had little information about her uncle, but what info she did manage to acquire from her parents' closest friends, he used to be a swordsman but did not serve under a lord or work for the government. Despite that fact, he was given a rather handsome salary and lived comfortably before he ultimately decided to rest his laurels and take up a life of comfort as a merchant in Shanghai. Assuming he was indeed a Demon Slayer, the same as Gyomei, perhaps he could offer her some form of training.

Of course, there was no actual guarantee her uncle was a demon slayer. This was all conjecture, but it was all she had. Besides, she had no other family. As the remaining heir of her bloodline, she would be expected to uphold it, however much it was worth in the grand scheme of things. In all honesty, 2B did not understand why bloodlines were so important to Japanese culture. Why was one's blood important when it came to matters such as political power, prestige and recognition? Was there some kind of underlying meaning that she could not see?

As the young girl disembarked and entered Shanghai, ignoring the odd stares she received along the way, 2B couldn't help but notice the faint mist that surrounded the city. It wasn't bloody red like the ones that lingered around the demons, but a mixture of colors. So disorienting was the clash of colors that she couldn't help but wince.

Ever since that fateful day a year ago, she saw these colorful mists lingering around people. She did not understand why she alone saw them, only that they somehow represented something. The intensity of the mist, its thickness, its color; all of these things gave away something about the person it lingered around that told her what she might expect. If the mist was thin and almost transparent with a soft or light color, then the person was sometimes meek or shy, but overall kind. If the mist was thick and heavy with a darker color, the person was likely to resort to violence easily. Those that were in between were mild-mannered, but otherwise had a hidden side to them.

She also noticed that almost none of the people she saw had that silvery mist like her father did. As to why that was, she was not sure.

2B did her best to ignore the pain the clashing colorful mists around Shanghai's residence caused her while she searched for the estate where her uncle was believed to be residing. It took her an hour of wandering and asking for directions whilst also avoiding some of the more unsavory characters before she finally discovered his location.

She realized her uncle had a handsome salary and likely amassed a fortune due to his occupation as a merchant, but she never expected for him to be living in such a grand place of residence. In terms of western design, it wasn't as grandiose as a mansion, but the elaborate design of use of concrete and wood certainly made it rather interesting. Pillars were used to uphold the roof of the front entrance while beams made entirely out of stone could be soon on the building's exterior, reaching all the way up to the tiled rooftops. The house extended at least six or seven meters on each side, two-stories tall with windows hiding the interior with dark blue curtains. There was a small but sizable garden sitting off to the side, while the entire premises was defended by stone walls and a steel gate, which 2B currently stood in front of.

"I see the life of a merchant and being funded affords a life of luxury." 2B noted to herself. "So this is what being rich looks like." She pressed her hand against the gate and slowly pushed it open with some effort.

The property between the gate and front door was a beautiful landscape. There were flowers planted across the walkway and various other plants that she couldn't quite identify. She approached the wooden oak door. Much to her chagrin, she could not reach the knocker that was danging in the middle of the door due to her short height. Instead, all she could do was knock as hard as she could without seriously injuring her hand. She gave three sharp knocks, then waited for a minute patiently. Just as she was about to knock again, the door opened to reveal a woman with dark hair and violet eyes, wearing a kimono with a yellow sash.

She blinked in surprise when she saw 2B, a mere child at the doorstep of a merchant. "Oh my, what brings you here, child?" she asked curiously.

"I am Yona." she greeted. "Is Isshin-dono home?"

"Oh? Japanese? So you're little Yona?" The woman questioned.

2B nodded in response.

"I see. Please come in, come in." She guided her into the household.

Yona bowed her head in gratitude, then stepped inside.

* * *

The man that was her uncle was her father's older brother. He was twelve years older than Yukito Tsukiko and was described as being of the stoic sort. At times he could be a drunkard, but above all else he was a family man. He never married because he felt that no woman could ever be attracted to a man who preferred to swing his sword at others, but that was not to say he was not attracted to the fairer sex. In his teenage years, 2B's uncle was said to commit acts of philandering and was known to cause trouble by courting the daughters of influential families in the region, only for said relationships to be casual with no actual meaning. The amount of trouble he caused was certainly troublesome, but each time the family came looking for revenge, they were met with steel. Especially when the offended parties attempted to hurt him by attacking his own kin.

Her father spoke very little about his brother, but meeting him personally, 2B couldn't help but compare him to Commander White in terms of intimidation factor. Though he was now at the ripe age of sixty, his hair developing large stripes of gray and wrinkles blotting his skin, his body was as fit as an athlete and his hands looked rough. He was old, but at the same time he was still full of vitality and fully capable of combat. The way he carried himself implied discipline, and the steely look in his eyes would have petrified a lesser man. A salt-and-pepper beard covered his lower chin, closely shaven but still long enough to hide his wrinkled skin. His yukata was dark with golden decorations along the left side.

The moment she entered the room, she could only feel his eyes bearing down on her and determining whether or not she was a threat. In response to such evaluations, 2B steeled herself and was ready for a battle at the drop of a hat, clutching her grandfather's blade with the intent of unsheathing it. She never once turned away from his eyes and returned the look, daring him to attack her.

She was no fool. She would certainly lose, especially in this weak body of hers, but she'd be damned if she would not go down without a fight.

"...heh. Good to see Yukito's brat grew up strong." A crooked smile adorned his face, pleased by what he had seen. The pressure that fell on the room dissipated and she relaxed her grip. "Yona-chan, right? It's been so long. Last time I saw you must've been, oh, maybe when you were still in your mother's womb. I suppose you know who I am already, but my name is Isshin. It's finally nice to meet you in person." His smile dimmed and his eyes turned misty. "A shame it had to be under these circumstances. How long has it been since...?"

"Fourteen months, six weeks and three days since my father's passing." 2B informed him. His eyes widened in surprise, not that she blamed him. After all, who expected a child to count down the days since the death of her family? "I spent that time under the care of one of otou-sama's close friends. I believe you received my letters."

He nodded. "I have. They give you any trouble?"

"None at all, though the village has been in dire straits since it was discovered that the village head was a demon."

"Understandable. Given the circumstances, anyone would feel the same." To learn that the leader of a village became a Demon and feasted on his fellow villagers while everyone was unaware. It was a terrifying thought. And to think there was another during the attack. "...And you said you were saved by a Demon Slayer who was fortunate enough to find housing with you and Yukito, correct?"

"Yes." She nodded. "He slew the village head...but we didn't realize there was another Demon until..."

secs agoShe trailed off as the memory played out in her mind. Those foreign, human emotions rose within her again and created no end of discomfort for her. She tried to quell the emotions, but only partially succeeded as they surfaced on her face for a brief moment. Her uncle nodded in understanding. "I see. Still, what made you decide to suddenly come here to Shanghai?"

"Because I wish to ask you something, Ojii-san." 2B told him. The man raised an eyebrow, curious when he saw her serious expression. "Were you a member of the Demon Slayer Corps?"

Her uncle chuckled. "I was, but that was a long time ago. And I believe you just answered my question. Still, I'll ask again." He leaned in, a strange gleam in his eyes. "Tell me, Yona... Why have you come here, to this hellish city?"

2B bowed her head deeply and begged. "I beseech you, Ashina Isshin. Please, teach me how to become a Demon Slayer."

* * *

**AUTHOR'S NOTE**: Drat. I was three days away from making it in time for Christmas. Oh well. Special thanks go to Daemon of Wrath for helping me complete this chapter.

Quick clarification that this is strictly a Kimetsu no Yaiba x NieR crossover. The character Isshin Ashina is based off of the character of the same name from the game Sekiro: Shadows Die Twice, but they are not the same person. Also, regarding the "vision" that 2B sees that helps her see without actually using her eyes, think of it like a bastardized version of the "see-through world." It isn't as effective, but it helps 2B out because it also helps her see things most demon slayers might not see. Granted, her "sight" isn't as good as the "see-through world" that others with the mark see, but it works well enough.

Another interesting to note is in regards to 2B's techniques. Seeing as how she is not a demon and lacks the abilities that Kokushibou has, she needs to use two swords to accomplish certain techniques. She's learned how to dual wield, but for the most part, she will only draw the sword on her back to use certain techniques. Also, be sure to remember that, in contrast to the raw power of the techniques Kokushibou uses, hers are nowhere near as powerful.

Also, regarding who 2B will interact with the most, I've decided to have her partner with Zenitsu. I don't really feel like rehashing canon events, the Final Selection Arc being the sole exception because it also gives you a glimpse between 2B and Tanjiro's future interactions and differing ideals.

On a side note, I finally got my hands on The Last Word exotic in Destiny 2. It's about damn time. Now all that's left for me is Thorn, Sleeper Stimulant and Malfeasance. And maybe whatever new Exotic I'm looking to get my hands on that doesn't require me to do a Raid. For the life of me, I can't form a party to save my life.

I hope everyone has a wonderful New Year, and on that note, while a few days late...

Merry Christmas, you filthy animals.

* * *

**REVIEWS**

Donjusticia: Warning. counter measures shall commence in T-minus X seconds. Please evacuate the facility.

Dxhologram: Perhaps, but she spent a majority of her life as a machine. Even though she's had twenty years, she's still learning how to understand and deal with humans. It's gonna be a while.

Guest (RedSazabert): Spoiler, expect either a mean right hook or a ten out of ten German suplex to occur within seconds of their first meeting.

The Neckbeard Knight: I contemplated giving 2B an original Breath, but ultimately decided against it. I felt that Breath of the Moon would have been a better choice, not to mention the fact that 2B's "home" was the moon itself.

Kensei-1085: She is not a descendant. She's simply one of the few people who still practices the techniques he created.

Yolea Irk's: That's a relief to hear. Hopefully, I can continue to get 2B's personality down pat while also helping her grow more as a "human."

fruitspunchsamurai-987: Indeed. It will definitely be interesting, learning how to write her character as a human instead of as a machine, which brings a whole lot of new things to consider.

Killer Hamster: As you can see, 2B's story is concurrent with Tanjiro's own, but she has five years over him since as of Chapter 2, 2B is now twenty years old.

Hakuryukou79: Indeed. Sanemi's already shown he doesn't have a good opinion about her, but that may change over the course of the story.

Guest #1: There is a reason why Dishwasher1910's artwork is used as the cover.

NoNameAvailable Bis: 2B's relationship with humanity is complicated, yes. Not that you could blame her, considering she was fighting for a race that's been extinct for who knows how many years. However, as they keep saying, feeling emotions is forbidden or something along those lines. Despite her feelings, her purpose for fighting is hardwired into her, reincarnation or no. Even if her feelings towards humanity may be complicated, she can and will fight to protect humanity. Of course, its coming to understand humans as well as the humans who've become demons themselves that will be the major points of development for 2B during her career as a Demon Slayer.

Guest (Andromeda): 2B will eventually become a Hashira, and yes, she will be the Moon Pillar. Fun fact: Her Hashira look is what is depicted in the cover art.


	3. 03

**DISCLAIMER**: I do not own Kimetsu no Yaiba or NieR. Both are properties of Koyoharu Gotouge and Yoko Taro respectively.

I do not own the cover art. All credits go to Dishwasher 1910.

* * *

**2B(a)DEMON SLAYER**

* * *

CHAPTER_03: Shanghai

* * *

"Shanghai, hm?" Ubayashiki smiled somewhat as 2B recounted her time with her uncle Isshin. Compared to the other times he smiled, however, this one was notably strained and more worried. "It's been a long time since I've heard of that place. I'm amazed you found the strength to make your way there, much less found the strength to survive there while training beneath a man so favored by the Shinigami."

The reincarnated android nodded in agreement. "My time studying beneath my uncle was not pleasant, and I crossed paths with death many times. However, it still proved an invaluable experience for me."

"Would you mind telling me about it?"

"Of course, Oyakata-sama."

* * *

_Shanghai, China._

_On the surface, it was a municipality city and one of the many places that fell to the influence of modern industrialization brought about by the west. People lived their lives there without fear or worry, save for the ones whose lives took a turn for the worst due to one reason or another. Along this line of thinking, it seemed odd that someone like Isshin Ashina, a skilled swordsmaster who could have become a Hashira, had sequestered himself in this place and opened up a trading company._

_But, Shanghai held a dark secret. One that I discovered for myself when my uncle accepted my request and began teaching me in the demon slaying arts._

_I was told of the workings of the Demon Slayer Corps and their purpose, how their weapons were forged and what demons were. The organization had existed for a very long time, but it had not been until a man bearing hanafuda earrings had appeared that it began to increase in power and influence. The demons that plagued Japan were slowly, but surely, being pushed back._

_Yet no matter how many demons we slayed, more would still come, for their progenitor and creator walked among us._

_Muzan Kibutsuji. That was the name of my enemy, and the identity of the man who created demonkind._

_By exposing his target to his blood, either by having them ingest it or expose it to an open wound, Muzan could turn a human into his thrall. Based on what records the Corps had to go by, the demons obeyed Muzan both out of fear and loyalty, and those who disobeyed him were destroyed by way of a deadly curse. Any demon who spoke his name was killed by the demonic genes that infested their being. In other words, a defensive mechanism to protect his identity and whereabouts._

_However, not all demons were loyal to Muzan. Some sought to increase their strength in the hopes that, one day, they may usurp their creator. Thus, many demons fled Japan and sought out other continents._

_Shanghai was one such place of refuge. In recent years, it became a festering hive for demons who sought to establish influence. It was for this reason that Isshin established a base of operations in Shanghai: To hunt down these demons and eliminate any others who dared enter his territory._

_This was how my first days of training began..._

* * *

"Again, Yona!"

2B gritted her teeth, trying to keep her breathing even. She kept the rhythm in her lungs steady, her breaths short and evenly spaced while also straining her body to adapt to the harsh regimen Isshin was subjecting her to. When her breathing became erratic or slipped for even a second, she was punished by a blow to the stomach that nearly made her vomit all across the training floor. She needed to maintain evenly-spaced breaths, neither too large or too big, while keeping her surroundings in mind. In other words, she required total concentration while being aware of any dangers approaching her that may take her off guard.

Said 'danger' was Isshin himself, striking at her with speed and swiftness seen only in YorHa executioners such as herself once so long ago. She was initially amazed by the fact that a human, especially one as old as Isshin Ashina, was capable of such movements, but that awe faded when she realized just how brutal he could be. It took every ounce of thought and muscle to either parry his blows or move out of the way.

Her instincts from those long years of battle had not faded, but her flesh-and-blood body could not withstand the same punishments or be forced to move like her old one. She would fail and suffer a blow, but she never allowed it to weaken her resolve or let it drag her down. She continued to force her body up to its feet and continue with the training.

In this instance, Isshin was training her in the art of Total Concentration Breathing - a technique that would allow her to increase the blood flow via a breath pattern, temporarily increasing her overall physical capabilities and give her an extra edge when combatting the demons. It was the first step in learning a Breathing Style, the swordsmanship used by the Demon Slayer Corps to defeat demons, but Isshin had gone a step further by teaching her a more advanced technique. That was to say, Total Concentration: Constant, in which she had to maintain her breathing patterns at all times, regardless of whether or not she was in the midst of battle or if she was asleep.

As she expected, it was difficult to maintain an even breathing pattern, especially when under constant assault. She did not quite understand why Isshin chose to teach her a technique that was meant for higher-ranking individuals in the Demon Slayer Corps, but she did not question it. If anything, learning an advanced technique early could prove beneficial, but only if she could use it properly.

While keeping her breathing even and steady, 2B momentarily lost her footing. She was about to hit the floor, but at the last second slammed her palm down and pushed herself into the air and onto her feet. Isshin capitalized on this brief mistake and lunged forward, his sword swinging faster than a human could perceive. It was only thanks to her previous combat experience that 2B managed to defend against the blow, but once again, her weak body could not fully defend against her uncle's mighty strike. Her hands trembled as they attempted to maintain a solid grip on her sword while the rest of her body shook from the impact.

"What's the matter? Are you getting tired? The demons won't give you the time to recover, Yona! Stand firm!"

2B paid no heed to Isshin's words. Her lungs contracted and expanded painfully while maintaining her breathing pattern. She did not know how long they had been fighting now, nor did she care. She only needed to memorize these sensations and understand them, control them to suit her purposes.

Once more, Isshin was upon her. And this time, she could not defend. His sword struck faster than it had previously and with much greater strength behind it. The wooden sword in her hand shattered into splinters and she sent flying, her back hitting the floor repeatedly like a floundering fish before coming to a stop. The breathing pattern was disrupted.

2B felt her chest explode in pain and suddenly found it very hard to breathe.

"Kugh...!"

Isshin looked down upon her defeated form. "Looks like this is your limit for now." 2B wanted to refute, but her gasping prevented her from speaking. "Let us rest for the day. Try again another time when you have recovered," he advised as he gently picked her up from the floor.

2B felt a semblance of irritation swell up inside her. Ever since Isshin began their training, she cursed her frail body more and more for being unable to replicate the abilities she was once capable of. It was understandable that it was impossible at present, given that her current body was that of a child, but it was still infuriating. More so now that she was being carried like some sort of child. She couldn't exactly voice her indignation about her current state, so instead she mustered the coldest glare she could and aimed it at the cause.

To her chagrin, Isshin only laughed. "If you keep that look, you'll find yourself with more wrinkles than I have." 2B scowled and turned away from him, making him laugh harder. "Don't feel ashamed of your failure, Yona-chan. Instead, learn from it. Constantly maintaining Focused Breathing is difficult, yes, but the more you attempt, and the larger your lungs expand, the quicker you will be to master what I will teach you."

The day 2B began her training as a Demon Slayer, Isshin told her what she would expect. After she learned how to control her breathing patterns and maintain it during combat, he would teach her the Breath Style she would use to combat the demons. There were multiple Breathing Styles, each with their own unique strengths and weaknesses. Isshin could recall at least four different Breathing Styles with the exception of the one he himself used.

Water Breathing was the most common Breath, and supposedly the easiest to learn. It allowed for the user to battle almost any opponent, suited for adaptive combat. It had few flaws, save for that the techniques themselves relied on the user to be just as adaptive as the Breath itself.

Wind Breathing was a style suited for those who wished to attack their opponents swiftly and without mercy. Each strike was meant to be powerful and executed so quick that the enemy would not have time to defend properly. It's flaw was that it required the user to be fast enough to sufficiently handle the speed in which they struck, and have the means to back the power behind the swing.

Thunder Breathing was a difficult style to learn. Like Wind Breathing, it specialized in speed, but forfeited power in favor of finesse and precision. Isshin described it in a manner similar to the sword style of iajutsu, or the "quick-draw" technique. In other words, to kill with a single blow. As such, its weakness lied in the user's ability to move at such incredible speed and deliver the first - and final - killing blow. They would have no chance to execute a counterattack should it fail.

The last was Flame Breathing, which was of a mixture of Wind and Water Breathing. It was simple to learn, but at the same time, the means to reach the full potential of Flame Breathing required putting the body through absolute hell. If the user could withstand the punishment and pain to learn and master it, they would be capable of matching even the strongest of demons.

"Which style do you practice, Ojii-san?" 2B inquired after he finished his explanation.

She recalled how sullen Isshin's face had been when she asked that question, or how his tone lacked his usual bitter tongue. "I am a cultivator for the Breath of the Moon. It is one of the oldest Breathes ever taught, and it is considered to be one of the most powerful. The speed of Wind Breathing, the power of Flame Breathing, the adaptive ability of Water Breathing, the defensive strength of Stone Breathing, and finesse of Thunder Breathing... You could say that is all five Breathing Styles in a singular form. Of course, that's what makes it so difficult to learn. It's also why I will teach you Total Concentration: Focused Breathing. If you want to have any hope of mastering this Breath, you will have to push your body to the absolute breaking point."

"Judging by how you describe it, it sounds as if Moon Breathing is unpopular, despite its usefulness if one can overcome the hurdles towards mastering it."

"You're smarter than you look, little one. And you're correct. With the death of my brother, and including myself and you should you learn it, there are only ten Demon Slayers in the entire organization who use this Breathing Style."

2B did not understand why there had been so few. A sword style that powerful, however difficult, would prove invaluable in the battle against the demons. "Why are there so few who use it?"

Isshin's answered, and she understood it then how confusing humans could be.

"Because the man who created it betrayed the Demon Slayer Corps. and became a demon."

A traitor's sword style. 2B could somewhat understand why they had been so reluctant to use it. Even so, she found it foolish for them not to look past it. The past was the past. The present was the present. If a sword style was used by a man they believed was evil, then they should take that sword style and use it for good purposes. It mattered not who created it, only how it was used. Sadly, the humans of the Demon Slayer Corps. did not seem to understand this and would rather it fall out of use.

If they would not use it to its fullest potential, then that was their mistake. 2B, however, would learn all that she could. She would master every swing, every technique, every single movement that Isshin Ashina had to teach her, and make it her own. The Breath of the Moon would become her sword to slay the demons, and nothing, not even the Demon Slayer Corps., would stop her from achieving this goal.

A month had passed since then. A month of endless training, of learning Total Concentration: Focused and maintaining it in the heat of combat. 2B had showed slow progress, but she knew better than to rush progress.

In the present, after she recovered from her recent bout with her uncle, they had taken to the dining room and filled their bellies with food. This was among the few things 2B had begun to enjoy when she underwent this "reincarnation" process humans spoke of. She felt a partial fondness for sushi in particular, recalling how she once engaged in fishing activities back during her days with YorHa and 9S. She even recalled how she once caught a trout and grouper fish and how delicious they looked once they were cooked.

Oh, how she envied the androids who were built with proper eating functions. She attempted to eat fish once, but being an Executioner-class android, she was not built with such functions and nearly shut down trying to digest it. That is why she was grateful for this new life of hers. Now a human, she was able to properly consume food. While it may be taken for granted by normal people, as it was a daily necessity, she viewed it as a great luxury as well. She enjoyed the sensation of tasting her food and feeling the texture inside her mouth. Even swallowing her food was a pleasant experience.

"Careful not to choke, gaki (brat)," Isshin chided her gently. "I'd hate for my first student in years to die to something as embarrassing as being too hasty with her food."

Somewhat annoyed, 2B regardless heeded his advice. As much as she considered food a luxury now, it was still nourishment and fuel for whatever training the man had planned for her next.

"What will be next? Will you have me practice Total Concentration: Constant breathing again?"

To her mild surprise, Isshin shook her head. "On the contrary. I believe it's time for some live field experience. When you first arrived here, I trained you to withstand punishment and how to wield your sword. And you've begun to learn Total Concentration breathing, even if you struggle to manage it in its Constant state. Regardless, I believe it is time for you to experience your first real taste for combat."

Years of restraining her emotions did nothing to quell the small sense of excitement that rushed through her the moment he said those words.

"Prepare yourself, Yona. This evening, you will begin hunting your enemy."

* * *

Kagaya Ubayashiki raised a brow, clearly having not expected to hear this. "Isshin had you hunt demons? Even though you trained for only a year?"

"By then, I was proficient with a blade, and though I had yet to fully master Constant breathing, I was able to use it well enough. Ojii-san believed that facing down a demon was the best experience for me in spite of the dangers."

"I see..." The blind man sighed deeply. "Given you are here with me, it's clear you survived your experience in Shanghai. Tell me, compared to the demons you fought in the Final Selection, how were the ones in China?"

"If I were to make an accurate comparison, it would be a captive animal compared to a wild one. I do not know how long the Demons on that mountain were captive, but they were definitely weaker due to being starved for most of the time. However, the ones in China had no such limitations."

* * *

2B wrinkled her nose, finding the tainted air in the industrial section to be rather foul. Her nostrils were burning from the acrid, oily scent of coal and oil being burned. If Isshin had any such problems with the smell as she was, he didn't show it.

"Why are we here in daylight? I thought demons could only be active at night."

Isshin nodded. "They are, and few are rarely mobile in the day. The braver ones tend to stay in the shadows, huddled in places where sunlight cannot reach. Such places are rare, but not entirely uncommon. That building across the street, for example. It was originally planned to be a factory, but plans for it fell through and it was abandoned. Now it's all boarded up."

She looked at the building Isshin told her of. To her surprise, there was a faint red mist flowing around it. It was nowhere near as strong as the mists that clung to the forms of the village elder and the demon that invaded her home, but it still told her of the presence of a demon.

"A demon has made that place its home?"

"Recently, there's been a string of murders around this street. Men around the age of thirty have been found dead, torn to pieces with their chests ripped open by some kind of vicious animal. With the exception of their left lung and heart, all other organs were shredded."

"Wouldn't people assume it was simply a serial killer? If that had been the trend of the killings, it could have been written off as the murderer's work signature."

"Under normal circumstances, most likely. But these wounds are far too sloppy to be made by a person. And the the way the left lungs and heart were untouched every time makes it seem too habitual for a random wild animal. Furthermore, given how Demons exist and the killings took place at night, it is most likely the work of one of Muzan's minions." Isshin turned to 2B. "Unlike the ones in Japan, the demons of Shanghai have come here, thinking they've escaped his grasp. They seek to grow in strength in places the Demon Slayers have not touched. Tonight, you will kill one."

2B frowned slightly. She had undergone only a year of training, enough time for her body to wield a sword properly, but nowhere near enough to build the strength necessary to put in the proper force require to kill a man with a single well-placed swing. "I do not mean to question you, Ojii-san, but will I be capable of accomplishing this? And with so little information to work with?"

"In our line of work, we always fight with so little information about our foes. How many people has this demon eaten? How long has it lived? Is it possibly one of Muzan's Twelve Kizuki? Does it know a Blood Art? There are even times when mere trainess such as yourself find themselves facing down a demon earlier than they expected. It is rather risky, yes, but should you survive, you will gain a great deal of experience and strength from it. The question is..."

Isshin's gaze turned critical. "Do you have the resolve and will necessary to face down a demon by yourself?"

2B paused and ran the question through her mind. Was she truly ready? From an objective standpoint, she was venturing into unknown territory. Her target was a demon of unknown strength and capability. It would have the field advantage due to the building being its home. While she herself only had a year of training and the body of a child. She didn't even have the proper strength for a single, clean kill. Worse still, the demons were capable of regeneration. If she left them alone for a period of time, they could recover.

She would need to strike as quickly as possible. If this was Isshin's next step for her to become a Demon Slayer, she would have no time to complain or argue. She needed to adapt.

"I will need time to adjust to the weight of a sword," 2B said after a moment. "An actual sword is heavier than a wooden one."

Isshin laughed. "That is is, Yona-chan."

* * *

By the time 2B had trained with an actual sword, heavier and more appropriate for her, it was evening. The sun had settled and continued to sink into the horizon. The sky was dark, little sunlight now peeking through buildings and the streets. A demon could waltz down the street without worry of being turned to ash. Upon arriving at the abandoned factory, she saw that the mist had grown thicker and more pronounced.

The demon was here.

She looked at the sword settled across her back. It was not a proper Nichirin blade, but it was capable of slaying a demon like any other. The tanto was short, but it was easily the most appropriate weapon for her. The katana proved too heavy for her, much to her chagrin. It still infuriated her that she was forced to use such a weak body to combat the enemy. It would have been a simple matter were she still an android. There was no use in crying over spilled milk, and no matter how much she found it irritating, she had to adapt to her new situation. She would simply need to strengthen her body and teach it how to move as she once did, or at the very least put it on a level where fighting demons was much easier.

With resolution, she stepped forth. The boards over the front entrance were worn, but there was enough space for her to crawl through the gaps. The factory was completely empty, save for what little machinery that was left here. They were covered in thick layers of dust, proof that they had not been used in some time. Her footsteps echoed as she ventured into the shadows. She could not see well in the darkness, but the faint wisps of mist told her all that she needed to know. The silence helped to hide the demon's movements, but the mist gave away their actions. 2B gave no indication that she knew they were there or that they were moving. She waited patiently for them to make the first move.

A minute passed.

The demon struck with a bloodthirsty roar.

2B jumped back and evaded the oncoming attack. The demon's attack did not touch the ground, yet even so, the ground was torn asunder by what looked to be a streak that followed after the swing. She put distance between her and the demon and unsheathed her tanto while taking in the appearance of her quarry.

The demon was female, black hair done in pigtails and skin pale white like the village elder and the demon that held her hostage. It wore a tattered yukata covered in red stains. Her eyes were dark green, pupils barely even visible.

"Aw, why did you dodge, little girl?" the demon asked in a surprisingly polite tone. It smiled even, showing off its fangs to her. "If you didn't, you wouldn't have felt a thing."

2B narrowed her eyes. 'The ground was cut, even though she did not touch it. A natural ability, or her Blood Art?'

"Heeey~ Don't you know it's rude to not answer when someone's talking to you?"

"I see no reason to converse with you," 2B replied coldly. 'For now, I should act defensively. I need to understand how she managed to cut the ground, as well figure out if her attack have a limit to its range.'

"Then just die then girlie~!" She grinned as she swung her arms. 2B reacted quickly and leapt backward. A second later, the ground she stood on was ripped by unseen blades.

_'Two slash marks, at least fifteen inches in length and three inches in width.'_

The former android rolled unto her back and on her feet, falling into a crouch with her tanto raised. The demon charged at her again. She dodged to the side and evaded a claw that would have grabbed her and smashed her into the wall behind them. She watched with morbid fascination as the demon's claw embedded itself in the wall, though whether or not that was an inconvenience to it, 2B had no idea as the demon dragged its hand through the wall while charging at her again. Concrete and brick flew as the demon tore its claw out from the wall and swinged at her. 2B ducked and saw the demon go in for a knee-strike. The knee flew right over her face while she leaned back, back-flipping away from her.

"Oho, you're spry!" the demon cackled. "But you look so small and frail. I bet just one hit from little ol' me, and your bones will break like twigs~"

She had no doubt about that. It was why she couldn't afford to let the demon hit her whatsoever. Of course, that would be easier said than done. 2B glanced back at the first slash mark. 'That one is seven inches in length, but six inches in width,' she noted. 'When she attacked me then, she was much closer to me than when she created the two slash marks just now.' If her guess was right, then the "invisible slash" she made grew smaller, but wider the closer she was, possibly promising a rather visceral death, while the further she was away from her target, the slashes were longer, but also thinner like a blade. 'Whatever it is, it is definitely a Blood Art of some kind.'

The question was how could she-?

The demon closed the distance, faster than she was expecting. 2B's eyes widened and immediately jumped to the side, evading a kick that kicked up a burst of air. The burst of air pressure that came as a result nearly knocked her into the air.

_'Her physical strength is higher than what I was expecting. So, this is what a demon can do in combat!'_

She dodged another attack, this one a roundhouse kick that would have knocked her head clean off her shoulders if it connected. The demon laughed as it threw its claw forward. 2B moved to leap to the side, but felt her shoulder slice open. Behind her, engraved in the wall, was a slash mark. Blood spurted in the air and stained her yukata red. 2B nearly lost control of her breathing, biting back a cry of pain as her whole shoulder felt as if it was being set ablaze.

_'W-what is this?! This pain-!'_ 2B stumbled and nearly fell on her face. She just made it behind one of the discarded machines when she saw the demon swing its arm again, creating another slash mark that cut into the machine, tearing it open and revealing its dead metal corpse in the process. _'I-I can't tell if this is a human response or the demon's doing! I can barely hear myself think! Why in the world are human's sensitivity to pain so high?!'_

"Kahahahahaha! What's the matter? Did you lose your nerve, little girl? the demon taunted. "If you want to play Hide and Seek, that's fine by me~"

2B bit the inside of her cheek to stop her cries from leaking out. She couldn't give away her position. She had to recuperate and try again.

_'Breathe in, breathe out. Evenly. Don't mess up the rhythm. Don't mess up the rhythm!'_

2B moved away from the machine, knowing full well the demon would chase after her. To her dismay, blood was trailing down her arm and dripping down to the floor. No doubt the demon would either follow the trail or smell the blood. The injury would hamper here immensely, especially since it lowered her chances of success.

_'I need to find an opening.'_ 2B realized. _'A moment to cut its head off. To do that, I need to get up close. But how?'_

She did not know the range of the Demon's attacks. While she may be able to deduce the general direction, she can't determine the exact length of her range. If she charged head on, she could end up right right into invisible blades. She needed to find and exploit the Demon's blind spot in order to get close enough.

She made it to the far end of the room when she heard the demon cackle, not far away behind her. "I found yooooouuuuu~"

2B quickly jumped out of the way, evading another gash. She examined it and saw that the slash etched into the wall was long and thin, much more so than the one the demon sent at her when her first attempt to kill her failed.

_'I believe I understand her Blood Art a little more now.'_ The demon bounced off the floor and onto the ceiling, using it as a launching pad to drop down atop the reincarnated android. 2B evaded and decided to take the initiative, using what strength she did have to slice off the demon's foot. The attack connected and the tanto cut through flesh and bone. It was more difficult than she expected, finding her weapon becoming more heavy the longer the fight went, but she succeeded. The demon stumbled and growled in pain, glaring daggers at her. _'Just now, I felt a small breeze of wind. If my guess is correct, then...!'_

"You're using wind pressure." The demon's eyes widened. 2B smiled internally, taking that as confirmation. "The closer you are to your target, the wider the attack is, making it difficult for someone to dodge, but the attack itself isn't long length-wise. But the further away you are, the less wide the attack becomes. You make up for that lack of width in length. I imagine that, if you attacked from outside and you were a good distance away, you could bring this building down on top of me with one swing."

The demon hissed. "Cheeky little brat..." To 2B's displeasure, the demon was already starting to grow their foot back. "But it doesn't matter if you found out about my little trick. I'll still kill you and gobble up your pretty little corpse~!"

"You can try."

_'Even if I figured out her trick, I still need to figure out how I can cut her head off efficiently._' She glanced around the abandoned warehouse, hoping to find something that might be of use to her. Her eyes eventually settled on something on the far left side of the room, right behind the demon. It looked like a grinder. _'If electricity still flowed through the building, I could easily trap her arm in there and-'_

Wait, trap?

_'...that is possible.'_

"And just where are you looking!" 2B quickly ducked, evading a slash that would have beheaded her and quickly dived back behind the safety of the ruined machine. "Get back here!" They screeched as they jumped after her. 2B ran around the machine before jumping on top of it.

She needed to time this just right. Assuming it worked, which was unlikely, she needed the demon to attack her directly. If it attacked her using its Blood Art, it would be meaningless. The best way to ensure it attacked her head-on was to force it into close-quarters combat. That meant she would have to agitate the wound further, risk getting injured even worse.

_'So reckless.'_ 2B chided herself before smiling softly. _'Nines must be rubbing off on me.'_

Just as the demon attempted to use its Blood Art, the movement in the arm and slight dilation in the demon's eyes being the signs she required, 2B leaped into action and struck. Even though the weapon she used had a shorter reach than a katana, she breathed. She need to strike swiftly, and knew just the form to do so. There was no time to question whether or not she could perform it without any repurcussions. This was a do-or-die situation. If she died, she died. If she succeeded, she would live to fight another day. Nothing had changed since her reincarnation. To fight by the sword was to die by the sword. On the battlefield, she would serve her purpose.

At the very least, however, she would kill this demon.

2B recalled the motions her father had made that day over a year ago. How his muscles contracted and how his chest swelled as he inhaled. His every movement, no matter how miniscule or small, had a singular purpose: to cut the enemy down then and there. She did not believe she could perfectly replicate it or mimic the motion perfectly, but she played the moment over and over in her head, studying and remembering every second.

Just as the demon brought its arm down, about to summon forth a blade of wind, she put her father's technique into action.

"_**Tsuki no Kokyū, Hachi no Kata: Getsuryū Rinbi (Moon Breathing, Eighth Form: Moon-Dragon Ringtail)**_!"

The second the tanto was swung, 2B felt something inside her body burst. Her muscles tore and pain erupted all over her body in an instant. Every string of muscle, every fiber, every ounce of flesh screamed in utter agony. Her lungs burned, unable to handle the sudden burst of strength that erupted from the motion much less the increased amount of breath she inhaled. After the technique was executed and the attack launched, her body stumbled and collapsed unto a knee.

She paid no mind to the agonized screams of the demon as its arm was sliced off by a crescent wind blade spawned from her strike. The pain was far, far worse than her training with Isshin earlier, where the tiniest misstep in her breathing had caused her to barely breathe properly. Even worse was that the wound on her shoulder throbbed angrily in protest. Blood now soaked the entire sleeve of her yukata. Her arm was completely numb.

2B understood now why Isshin Ashina wished for her to grow her body in strength and perfect Total Concentration: Constant before attempting any of the Breath of the Moon's repertoire of techniques. What would happen if she had attempted to do this with only Total Concentration Breathing alone, and when she started her training?

"You bitch!"

The demon's playful attitude was gone entirely. Rage now enveloped her features. Blinded by her anger, she lunged towards 2B with a claw ready to impale her. The next course of action would be to move out of the way, but the agonizing pain in her body made it difficult to do so.

_'Move. Move. You must move.'_

Her knees buckled and knocked. Her body trembled, paralyzed and unwilling to react. The demon was getting closer to her.

_'You are my body. You move because I order you to move. Move. Move!'_

The claw was inches away now.

_'MOVE!'_

2B barely managed to pull her body to the right, evading the claw by a hair's width. It flew past her and tore into the grinder. The adrenaline in her body was working overtime. For a brief moment, the pain her body dulled but the aches remained. The demon glared at her and tried to pull her arm out, but received some resistance. Her claw was stuck, caught in the metal she tore through. The jagged edges and blades of the grinder dug into her skin. For a demon, this was only a minor inconvenience and would take only a moment.

The reincarnated android was faster. She did not have the strength to swing her tanto, but she had another means of fighting. She bit down on the handle of her tanto and inhaled. Her lungs were on the brink of tearing themselves apart, barely able to handle something as meager as Total Concentrated Breathing. She pushed through and struck with all her might, swinging the blade in her teeth into the demon's neck. A howl rumbled through her throat as she pushed the tanto further and further, tearing at the demon's throat with it. Two seconds later, 2B succeeded and snapped her head in the opposite direction. Her tanto cut through the air, and following it, a guyser of blood. Warm, red liquid splashed down upon her beaten form.

The demon's body stilled and staggered, standing in place for only a moment. The second its head touched the ground, bouncing off and rolling towards the corner, its body kneeled and began to break down into ashes. Its expression formed into disbelief and shock.

"N-no way... I died... I died to a child?!" The demon would have said something else, but it too broke down into ashes.

After ten seconds passed, nothing remained of it.

2B looked upon the remains of her target smugly before she felt the adrenaline in her body fail her. Her tanto became too heavy and dropped from her mouth, clattering to the ground. She hit the floor soon after, lying face-down.

_'A low-level technique by Ojii-sama's standards, and yet it caused me to be brought this low,'_ 2B grimaced. _'If the Moon-Dragon Ringtail did this to my body, I can't begin to imagine what the others would do.'_

As she laid there, she thought what to do next. Obviously, her next course of action was to stop the bleeding before she died of blood loss. She must have already lost a pint or two of blood. The problem was that she did not possess the strength she needed to actually do such a thing. Her body refused to move, too damaged to follow simple actions. A major complication, one that gave 2B cause for concern. She knew Isshin was nearby, seeing the silver mist growing closer through the thick red-

_'Wait.'_ Panic settled in her stomach. _'The demon is dead, and yet...the mist. It hasn't faded. That means-!'_

A shadow descended upon her. Before she had time to realize what happened or attempt to move in spite of the condition she was in, her body was sent flying. She felt her bones crack, the sound echoing in her ears. She coughed up blood when she hit the ground, rolling on her side.

_'Shit. My ribs...!'_

"Unbelievable. To think that big sis got killed by a little girl...!'

2B looked up. Two demons, both dressed similarly to the one she killed, stood where she slew the first one. One had red hair pulled back into a long ponytail whereas the other's cascaded down past her shoulders and stopped at her biceps and chest. Both had eyes filled with malice, pupils thin and narrow.

"There..." 2B wheezed. "T-there were three of you?"

"That's right. You didn't think there was just one of us here, did you? Rookie mistake."

"And your last."

This was bad. Very bad. She had no strength to fight anymore. She was easy prey. The demons advanced toward her, one flicking their claws while glaring down at her. There was no question as to what would happen next.

"I would appreciate it if you kept your hands off my niece, if you would."

The demons turned around, startled by the sound of Isshin Ashina's voice. 2B could saw him approach, walking leisurely without a care in the world. At his hip was a sword.

"Huh? And who are you?!"

"Another human?"

Isshin did not respond, he crouched down and placed a hand on the hilt of his sword. "_**Tsuki no Kokyū, Ichi no Kata: Yamitsuki - Yoi no Miya (Moon Breathing, First Form: Dark Moon - Evening Palace)**_!" With a swift motion, he drew the katana from its sheathe. With it, numerous crescent slashes followed and tore through the two demons like paper.

2B's eyes widened, watching in awe and fascination as the demons fell apart into literal pieces that broke down into ashes.

_'So quick, and in the blink of an eye!'_

Isshin swiftly sheathed his blade and rushed over to his injured niece. "Are you alright, Yona?" 2B would have said something, but her chest was in flames metaphorically speaking. Her lungs were barely functioning as is. "Did you use a Form?" She nodded. Isshin looked disappointed and impressed at the same time as he pulled her into his arms and pulled her away from the ground. "I don't know whether to call you foolish or a genius." He laughed when she shot him a glare. It was him who ordered that she hunt the demon down, so it was technically his fault that she was in this state. "I've known few students your age who knew how to use a Form with barely a year's worth of training. You should feel proud of yourself, Yona-chan."

* * *

2B finished recounting her tale to the leader of the Demon Slayer Corps. She took a small breath, recollecting herself from her momentary feeling of irritation with her uncle and teacher for nearly getting her killed (despite the fact that she was never in any real danger to begin with since Isshin was nearby). She saw Kagaya let out a deep sigh of irritation.

"Honestly!" he bemoaned. "If Isshin were still in my employ, I would have had words with him."

"Even so, his teachings, no matter how extreme, proved useful," 2B countered. "I gained necessary combat experience fighting demons in Shanghai. After two years of training and battle in the field, I was able to begin learning the Breath of the Moon properly. As I expected, though, learning the techniques proved to be rather difficult. Of the ten techniques Ojii-sama taught me, I have only mastered seven."

"I see. That is good. Given how difficult the Break of the Moon is to master under normal circumstances due to its chaotic and swift movements, you are doing quite well."

"Thank you, sir."

Kagaya smiled gently. "Please, call me Ubayashiki. Out of curiosity, do you know how many demons you killed during your time in Shanghai?"

"I cannot recall."

"I see..." He took a final sip from his tea. By now, night had descended and the sky turned dark. Both cups were devoid of liquid. "Thank you for speaking with me, Tsukiko Yona-san. The Demon Slayer Corps. is truly grateful to have you among its ranks. It has gotten rather late. If you'd like, I can prepare you suitable lodgings before you return to Kyoto."

"Thank you, Ubayashiki-dono." 2B bowed her head in gratitude.

Kagaya called for some servants to escort her to her temporary lodgings for the night. Once she was gone, Sanemi announced himself and requested to enter. Kagaya gave him permission. The scarred Hashira stepped inside and kneeled before his commander.

"Oyakata-sama, if I may. Why did you want to speak with Tsukiko Yona?" Sanemi asked out of genuine curiosity.

"I wanted to see her character for myself. There are so few of us who chose to take on Moon Breathing as their sword. I am well-aware of the Breath's troubled history." Kagaya sighed deeply and shook his head in dismay. "It is a shame that such a swordstyle is seen with disgust due to its creator. It is true that the one who created the Moon Breathing became a demon, but even something that was created by evil could be used for good."

He tilted his head and addressed the Wind Hashira. "Do you not agree, Sanemi-kun?"

The scarred man remained silent in thought. To be honest, the fact that a member of the Corps. willingly became a Demon filled him with disgust. Why would anyone want to become something they hated and hunted down? He could not understand. Still, there was no denying the lethality of the Breath of the Moon. He seldom saw it in action due to its rarity. But it is definitely a potent form to use. Assuming that this Tsukiko girl did not repeat the actions of her predecessor and betray the Corps, he saw no problem with her.

"...I believe so, yes."

* * *

When morning arrived, 2B bid her farewell to Kagaya Ubayashiki and the Wind Hashira, the latter watching her like a hawk as she left. The trip back to Kyoto was done entirely in silence. By sunset, she was back in Kyoto and in her lodgings. Isshin had bought her a small apartment near the outskirts of the city. It was located in one of the quieter parts, which 2B was thankful for. The few times went out into the heart of the city, she had nearly been overwhelmed by the huge amount of traffic of people and loud noises that bombarded her constantly. Somehow, Kyoto in full swing was worse than Shanghai.

For the next few days, 2B spent her time practicing her sword swings and meditating while awaiting her swords and uniform to be delivered.

It was on the fifth day that she received a peculiar visitor. It was a man, garbed in a pale white robe with a black haori with chin-length black hair. He carried with him a bundle of cloth in his arms. What made him so peculiar was the hyottoko mask over his face, preventing 2B from seeing his features properly. The mist that clung to him was dark gray, almost like smoke.

"You are Tsukiko Yona-san, yes?" the man inquired politely. She nodded. "I am Kanamori Kozo. I am here to bring you your uniform and swords."

2B bowed. "Thank you for delivering them, Kanamori-san." She ushered him inside her apartment and led him to the main room. She offered him tea, but he respectfully declined the offer.

Kanamori kneeled down and set the bundle of cloth down in front of him. He then undid the wrapping, revealing two swords, one the length of a katana and the other was an ōdachi. Both were sheathed by black scabbards, a white insignia reminiscent of a scimitar engraved near the top of the sheathe. The katana had a simple silver circle-shaped hilt with a crescent moon engraved on the left side, the handle colored white with black diamonds running down the middle. The pommel was silver with a glass black orb at the bottom. The ōdachi bore a similar guard, but instead of a crescent moon, a full moon was engraved into the hilt. The grip expanded as it neared the hilt, bearing a similar design as the katana only in reversed. The pommel of the ōdachi was black with a dark gold circle in the middle, and attached to the end was a white-and-black tassel.

"It is rather unusual for someone to request two blades, much less an ōdachi," Kanamori said as 2B held the blades. The katana felt right in her hands, as if it was made for her, while the ōdachi held a heavier weight to it. "How do they feel?"

"Perfect. I apologize if my request seemed odd."

Kanamori waved a hand in dismissal. "It's fine. Truth be told, I received another unusual order. Someone also requested two swords to wield instead of one."

2B hummed in curiosity, wondering what sword style required the use of two blades before she unsheathed the katana, giving it a swing. It easily cut through the air. For a moment, 2B felt as though she was wielding her old weapon again. She then held the blade up and watched as the steel began to change color. It was subtle and barely noticeable, but she noticed it.

"A silver nichirin..." Kanamori breathed. "This is my first time seeing one."

She looked at the swordsmith. "What does it mean?"

"I am unsure," he admitted to her disappointment. "It's said that the color of the nichirin imparts a special property to the sword, but I don't think I have ever seen a silver nichirin before."

"I see." She hummed. While she was disappointed that he didn't know the meaning, she was satisfied nonetheless. The color reminded her of her old sword. "Thank you for your hard work."

"It was no trouble!" The swordsmith then handed her a bundle of clothing. "This will be your uniform. It's light-weight, water and fire resistant, and very durable. A weak demon can't hope to tear into it."

Kanamori briefly removed himself from the apartment so she could change into it. When he returned, she was now clothed in the proper attire of a Demon Slayer. Much like with her swords, 2B was able to request some modifications to her attire. Instead of the traditional pants, she wore a black skirt with a blazer over a white-buttoned shirt. A white belt was strapped around her waist, meant to act as a holster for her katana. She also wore thigh-high black leggings. She also replaced the cloth wrapped around her eyes with a black strip of cloth, made with the same materials as the uniform.

"How do they fit?" Kanamori asked her. "Too big? Small?"

"They are fine. Once again, thank you for-"

She was interrupted by the sound of a loud 'CAW! CAW!' Her attention was drawn to her window as a crow perched itself over the windowsill. She recognized it as the Kasugai Crow that was assigned to her during the Final Selection.

"Tsukiko Yona!" 2B spluttered. It could talk? Since when could crows talk?! "Orders from the Demon Slayer Corps! You are to head to Kyōtango! I repeat! Tsukiko Yona! Orders from the Demon Slayer Corps! You are to head to Kyōtango immediately!"

"What? What do you mean?"

"Your orders! Your orders!" The Crow cawed. "Your First mission! Head to Kyotango immediately!"

"Well, looks like it's time for you to set out." Kanamori stated. "I wish you best of luck Yona-san."

Although still confused over the fact that an avian creature was capable of human speech when records stated that only a select type of bird could mimic human speech patterns, 2B nonetheless accepted the task given to her. Kanamori took his leave shortly afterwards. Before she set out, 2B began making her preparations. The journey to Kyōtango would be a long one indeed. She gathered the necessary supplies; food, water and anything else a human may require, before she paid her respects to the shrine built in her bedroom.

"I will be leaving now, otou-sama, okaa-sama."

The photographs of her parents in this life said nothing in reply. 2B did not quite understand why people would pray to a shrine built to honor their parents. Once someone was dead, that was it. They were gone, remembered by only those they left behind. Perhaps was because humans felt sentimental or superstitious.

She glanced over her shoulder, giving one last look to her apartment building. She imagined this would be the last time she would be seeing it for a long time.

She inhaled, then exhaled, and stepped outside.

Thus, in full earnest and blade in hand, YoRHa No. 2 Type B, walked toward her new battlefield.

* * *

**AUTHOR'S NOTE**: So, before I get into the actual details, I'd like to address something real quick.

A couple of days ago, I received a rather rude review on my fanfic "Kamen Rider Zero-One: Edge of Dawn" from a user by the name of striberz, not to be confused with the author striberx, who offered no actual criticism and feedback and seemed more invested on lambasting Fennikusumaru, a Kamen Rider fanfiction author (now goes by KR Duelist) since that story uses Fennikusumaru's OC, Kurogasa Kururugi. I informed him via message to offer some actual feedback, then proceeded to block him as I did not want him to start going on a rant or give him any further time of day. I have little tolerance for haters and trolls.

Not long afterwards, I guess I must have pissed him off because all of my stories got review-bombed by either him using another account or a friend of his. The actual "review" itself was nothing more than pure and utter Nazi fanfiction. Not helping matters is that all that's written on the profile page was "All unworthy fanfics will be raped." He previously used the name "rapelordcocker" but then changed it to Kristofer Viloria for whatever reason.

I'd like to address this person for a moment.

First of all, you ass, I am a proud Jewish bitch. Fuck the Nazi is a family creed.

Secondly, you need professional help. I mean, really? Writing all that? Do you have nothing better to do with your life or are you just that pathetic?

...okay, done with my rant.

:D

I've since deleted the reviews of both striberz and this "rapelordcocker", including the string of review bombs on Edge of Dawn. I don't expect them to stop after this, though I don't intend to stop writing either.

Honestly speaking, I feel accomplished that I pissed off a troll that badly.

There's not much to say about this chapter, except that Isshin Ashina has a rather interesting approach when it comes to teaching. Namely in that 2B, at that point, only had a year of training and only knew the bare basics of Moon Breathing. And what does Isshin do? Throw her at a demon, which nearly gets her killed.

Not what you call the best teacher.

To be honest, I feel dissatisfied with how the fight went. I feel like more could have been done with it, but what do you guys think? Any thoughts?

Special thanks go to Daemon of Wrath, who helped co-write this chapter. This story also has a TV Tropes page, so perhaps you could check it out and expand it?


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